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Acute stress reduction with interactive guided imagery in overweight Latino adolescents

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Acute stress reduction with interactive guided imagery in overweight Latino adolescents

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ACUTE STRESS REDUCTION WITH INTERACTIVE GUIDED IMAGERY IN
OVERWEIGHT LATINO ADOLESCENTS

by

Christianne Joy Lane

A Thesis Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
MASTER OF SCIENCE
(BIOSTATISTICS)

August 2007

Copyright 2007 Christianne Joy Lane

ii
Acknowledgements

Many thanks to Dr. Marc Weigensberg, who shared his exciting and unique study with
me, allowing me to pester him with lots of questions, and who played coffee fairy when I
needed it most. I would also like to thank the Imagine Team, who worked so hard and
carefully to collect the data used here. To Dr. Stanley Azen who supported my detour
from psychology and helped refocus my career. Finally, I am most grateful to Dr. Louise
Kelly, who generously read all the drafts of this paper, and whose helpful critique helped
me turn it into something I was willing to show others.
iii
Table of Contents

Acknowledgements ii
Table of Contents iii
List of Figures v
Abstract vi
Introduction 1
Obesity epidemic among adolescents 1
Behavioral pathway 5
The use of Mind-body therapies in adolescents for stress reduction 11
The study population: Stress and Obesity in Adolescence 13
Research Aims 16
Hypotheses 16
Methods 17
Sample and Study design 17
Measures 17
Procedure 20
Results 22
Participant Characteristics 22
Stress Reduction Pre-to-Post Session: Acute Effects of
Interactive Guided Imagery 23
Longitudinal Trends in Stress Declines 27
Discussion 30
Bibliography 36
Appendix A 42
iv
List of Tables
Table 1. Correlation of Salivary Cortisol with VAS 23
Table 2. Acute Stress Measures Pre- & Post-IGI Session 23
v
List of Figures
Figure 1. Conceptual Model of Stress & Obesity 2
Figure 2. Tanner Stage for IGI and Control Groups (p = .07) 22
Figure 3. Effect sizes of Salivary Cortisol Acute Response Across Sessions for
Interactive Guided Imagery (IGI) and Control Groups 23
Figure 4. Correlation of Pre-Session Salivary 26
Figure 5 Correlation of Pre-Session VAS to Change in VAS 27
Figure 6. Salivary Cortisol Estimated Marginal Means (+ SE) 28
Figure 7. VAS Estimated Marginal Means for Pre-Session and Acute Decline 28
Figure 8. Salivary Cortisol Estimated Marginal Means (+ SE) 29
Figure 9. Number of Home Practice Days Reported Weeks 1-3 32
vi
Abstract
Objective: This pilot study examined whether a 4 week program of Interactive Guided
Imagery (IGI) could reduce physiological and psychological stress in overweight, Latino
adolescents.
Methods: Twelve overweight Latino adolescent (6 girls, 6 boys) were randomized into
either IGI treatment or Control groups. The IGI group received a weekly 45 minute IGI
session while controls received no treatment. Salivary cortisol was taken pre- and post-
session in both groups. The treatment group also completed a measure of psychological
stress pre- and post-session. Both acute (within session) and trends in acute response to
stress (over 4 weeks) were examined.
Results: There were declines in salivary cortisol within sessions attributable to the IGI
treatment from the first session. The psychological stress measure did not consistently
respond to IGI over the study. Conclusion: IGI has great potential to decrease stress in
Latino adolescents, was well received, and results were almost immediate.
1
Acute Stress Reduction with Interactive Guided Imagery
in Overweight Latino Adolescents
Obesity epidemic among adolescents
Pediatric obesity is at record levels in the US
37, 38, 63
, as well as through much of
the developed and developing world
22
. Over 30% of US adolescents aged 12-18 years
old are considered at risk for overweight (BMI ≥ 85
th
percentile) and 16.1% are
overweight (BMI ≥ 95
th
percentile)
37
. These rates are higher among Mexican American
adolescents than Caucasian adolescents, where 40.7% are either at risk for overweight or
are overweight, and 22.5% are overweight
37
. Being overweight in adolescence puts an
individual at greater risk for being overweight as an adult, and brings with it the negative
health outcomes associated with obesity.
18
However, it is increasingly evident that the
long-term effects of adolescent obesity are not the only concern, but that there are more
immediate obesity-related physiological health conditions being experienced by obese
children including type 2 diabetes and metabolic syndrome.
13, 18, 32, 33

In addition to the physiological outcomes associated with obesity, being an
overweight adolescent can also be a stressful experience due to weight-related
discrimination
18
and feelings of low self-esteem, anxiety, and depression
40
related to
weight. In addition to this psychological toll of being overweight, recent literature
suggests that physiological stress may also be associated with some of the same negative
health outcomes as obesity itself, including cardiovascular disease
54
. However, stress is
not just a result of obesity, but may also be a cause of obesity
24
. The increases in
adolescent obesity seen today may be at least partly explainable by increases in stress.
Adolescents today experience higher levels of anxiety and stress than in previous
2
generations
68
. Twenge (2000) reported that the anxiety level of children have increased a
full standard deviation from 1952 to and 1993. They report that the anxiety levels of an
American child in the 1980s was greater than a child psychiatric patient in the 1950s, and
cite an increase in environmental dangers such as gun violence, and a decrease in social
connectedness as causes for this trend. This trend is increasing with time and it is
expected that stress in adolescence will continue to rise
68
.
The association between stress and obesity is complex and difficult to tease apart.
There are two proposed mechanisms by which stress may lead to obesity: (1) the
hypothalamic-pituitary-adrenal axis (HPA axis), and (2) the behavioral axis (see Figure
1). Each of these mechanisms is described in below.
Hypothalamic-Pituitary-Adrenal (HPA) axis
The HPA pathway exists as part of the stress response system and acts to help an
individual react to an acute stressor. When stimulated, there is a cascade of responses
ending in cortisol release. Cortisol is, therefore, an objective indicator of the stress that an
individual has experienced. The HPA axis includes a negative feedback loop so as to
prevent excess cortisol secretion, which can be very damaging
6, 11
. Thus, in times of acute
stress, increases in cortisol feed back to the HPA axis, inhibiting it and returning the
organism to homeostasis. However, when the organism is under chronic stress this effect
is reversed, so that the HPA is stimulated and remains in a heightened state
15
. The
resulting dysfunction in the HPA axis can have serious physiological results. Abnormal
functioning of the HPA axis is associated with many conditions including obesity, low
Figure 1. Conceptual Model of Stress & Obesity
3

IGF-1 and LDL cholesterol, and high insulin, glucose, triglycerides, LDL and total
cholesterol, blood pressure and heart rate
6
, as well as metabolic syndrome
11
.
4
In their review of a model of chronic stress and obesity, Dallman et al (2003)
discuss three mechanisms in rodents by which high concentrations of glucocorticoids, the
product of the HPA axis, due to stress act that can predispose one to obesity. First
glucocorticoids affect the nucleus of the amygdala, increasing the impact of
corticotropin-releasing factor (CRF) messenger ribonucleic acid (mRNA) facilitating the
chronic stress-response network. In addition, glucocorticoids intensify the experience of
pleasurable activities including eating sugar and fat laden “comfort” foods. Finally,
glucocorticoids increase abdominal fat. Of course, these mechanisms work
synergistically to increase body fat, particularly visceral fat, which can produce its own
cortisol. In obese individuals, particularly those with central obesity, the HPA axis is
hyperactive
6, 11, 43, 55
, which leads to a condition of “functional hypercortisolism” creating
metabolic changes similar to Cushings syndrome
55
including insulin resistance and
abdominal obesity.
Pasquali and Vicennati
55
discuss how this functional hypercortisolism is the result
of two alterations that disregulate the HPA axis. In the brain, after experiencing a
stressful event, stimulation of the hypothalamus results in a release of corticotropin-
releasing hormones (CRH) which, in turn, increase the secretion of adrenocorticotropic
hormone (ACTH) by the pituitary gland. ACTH stimulates the release of glucocorticoids,
such as cortisol, in the adrenal cortex. In addition, there appears to be supranormal
cortisol production in the liver and visceral adipose deposits. Thus, both mechanisms are
indicated (and measurable) by cortisol levels
55,56,69
. These high levels of cortisol “may
have a negative impact on the regulation of postprandial fuel metabolism and on insulin
action in peripheral tissues”
55
(p. S48).
5
In humans, there is evidence that high cortisol is related to obesity, and especially
central adiposity, in adults. For example, Rosmond et al. (1998) found consistent
relationship of cortisol measures taken at various time of day with obesity factors in a
sample of 1302 Swedish men. Spearman correlations with stress-related cortisol
(weighted for intraindividual variance) and BMI was .34, r
s
= .45 for waist:hip ratio, and
r
s
= .47 for sagital trunk diameter. High levels of cortisol are also associated with how an
individual copes with stressful events, particularly in those with central adiposity.
Wajchenberg
23
and Eisenmann
25
compared the cortisol secretion of premenopausal
Caucasian women with central obesity to those without (based on waist:hip ratio) on a
series of laboratory tests over 4 days. They found that a high waist:hip ratio was
associated with greater stress, both psychological and physiological as measured by
salivary cortisol than women with low waist:hip ratios. This was true in both lean and
overweight women. In lean women with high waist:hip ratios, the adaptation to cortisol
effects were higher and these women showed the least amount of adaptation to laboratory
stressors. The authors concluded that “central fat distribution is related to greater
psychological vulnerability to stress and cortisol reactivity” (p. 623). An extensive review
of the literature did not unearth published studies looking at correlations of obesity and
cortisol in adolescents, although the literature suggests that experiencing chronic stress as
a child may be related to symptoms of metabolic syndrome, one of the features of which
is central adiposity.
9

Behavioral pathway
The other proposed mechanism by which stress may lead to obesity is through the
use of unhealthy coping mechanisms to deal with psychologically stressful situations. In
6
regards to mechanisms of obesity, unhealthy eating behaviors and lack of physical
activity are the main coping mechanisms of concern. It is primarily these two behaviors
that influence energy balance, and both can be influenced by stress.
Stress and eating
There are several reasons why eating may be a natural response to stress. Eating is
both a necessary and pleasurable behavior. Eating can alter one’s mood, reduce
irritability and increase calmness
30
. For both humans and animals, the act of eating sweet,
fatty food is associated with calming
30
. This link is formed in infancy, when the food
being consumed is mother’s milk, both sweet and high in fat content. With maturity,
individual differences arise around the strength of this bond, reflecting differences in
predisposition, gender, and experiences
30
. Added to this are behavioral habits that are
formed around eating food when faced with a stressful situation. Many studies in both
adolescents and adults have shown that increased eating is a common response to stress.
There is evidence that this association is stronger in a person who generally eats less that
he/she would like, that is, those who can be described as restrained eaters
35, 52
. Those
who generally restricted their food intake were more likely to increase food intake when
stressed, than those who did not restrict food intake. This effect on restrained eaters is
found regardless of body weight,
35,58
and there is some evidence that it may affect women
more strongly than men
35
.
Cartwright et al.
8
reported on stress and dietary practices in adolescents from the
Health and Behavior in Teenagers Study (HABITS), which was drawn from an ethnically
and socioeconomically diverse population. This sample of 4320 children (Mean age =
11.8) used self-report questionnaires to measure stress and reported eating. They divided
7
their sample into self-reported stress quartiles and found there was a monotonic increase
in the amount of fatty foods consumed by stress quartile. When compared to the least
stressed, children in the other (i.e. more stressed) quartiles were significantly less likely
to eat >= 5 fruit and vegetable servings a day. The highest stress quartile did significantly
more snacking than the other quartiles, though the type of snacks the adolescents were
consuming was unspecified. In this sample, there was no significant effect of gender,
weight, or sociodemographic variables in reported diet. The authors concluded that these
unhealthy food intake trends were partly responsible for increasing long-term disease
risk.
Fulkerson et al.
28
analyzed another large sample of ethnically diverse adolescents
to examine links between depressive symptoms, eating behaviors, and physical activity
levels. Analyses of this sample of 4734 middle and high school students were stratified
by gender and compared students with low, moderate, and high levels of depressive
symptoms as measured by a 6-item scale that included items about anxiety and tension
that had been previously validated for clinical relevance.
42
Both boys and girls showed
significant differences in eating attitudes (caring about eating healthy foods, caring about
staying fit and exercising, and preference for unhealthy food) by depressive symptoms.
Those who were more depressed cared less about healthy behaviors and preferred
unhealthier foods. There were also negative monotonic relationships between eating
meals (breakfast, lunch, and dinner); depressive symptoms were associated with eating
fewer regular “formal” meals, no matter what meal it was. There were no significant
differences in reported snacking between groups. However, portion size was not
measured. For boys, there was a significant decline in the amount of time in moderate-to-
8
vigorous activity as depressive symptoms increased. This exercise effect was not found in
girls, however depressed girls reported spending more time watching television than non-
depressed girls. There were no differences for television watching found in boys. These
differences were moderate (less than .50 standard deviations) in size.
Several studies of adults have shown a link between stress and increased food
intake.
35, 46, 49, 52, 71, 73
Self-report of stress and eating behaviors in 212 undergraduate
students (primarily female (70.8%) and Caucasain (69.8%)) showed that most (73%)
reported increasing snacking, especially on “snack-type” foods when stressed, and also
decreasing “meal-type” foods such as meat, vegetables, and fruits
52
. Using 4-day food
records in 14 adults (3 men and 11 women) during times of high work stress and low
work stress, McCann et al.
49
showed that high work stress was associated with eating
more calories, more fat, and having a higher percentage of dietary calories come from fat
in sample of university employees. This finding was also shown in a larger sample of
adults (n = 90, ethnicity not specified) by Wardle et al.
71
who sampled participants 4
times over 6 months. In addition to the increases in food consumption found in times of
high stress, this sample also showed that restrained eaters, those who generally restrict
their food intake, were most vulnerable. There were not significant differences found in
individuals’ weight between low and high stress times.
In addition to positive memories and associations of comfort foods, there are
biochemical reasons for the calming effect of certain foods, which can influence cortisol
levels. Meals high in carbohydrates and low in protein will tend to make one relaxed and
calm, whereas meals high in protein will increase positive affect
30
. The neurotransmitter
serotonin requires tryptophan (TRP) obtained through diet to be synthesized
30
and there is
9
evidence that high-sugar, low protein foods increase synthesis of serotonin vs. low-
carbohydrate, high protein meals by raising the plasma ratio of TRP to other competing
amino acids vying for bonding to serotonin receptors in the brain. Low serotonin has long
been associated with anxiety and depression. However, this effect is largely influenced by
the carbohydrate-protein ratio, since protein can also improve mood through inducing a
rise in plasma tyrosine, which is a "precursor amino acid for synthesis of the
catecholamine neurotransmitters, dopamine, adrenaline and noradrenaline"
30
(p. 57).
Interestingly, these acute effects of high carbohydrate or high protein are reversed when
chronically eaten. Chronic consumption of fat makes one lethargic, though effects of
changes in fat are much less than in carbohydrates or protein when subjects are unaware
of the fat content, but when they know the fat content, more stress is associated with
eating it; this is especially true in women.
30

Stress and physical inactivity
The view of physical inactivity as a separate construct from physical activity
17
,
and not just a difference in level, is fairly new concept and therefore there is a paucity of
data looking at the link between stress and physical inactivity in adolescents. While
moderate intensity physical activity can be a great stress reducer, it may not be the first
response of many people when faced with chronic stressors. Hurwitz
39
reported on a
sample of 2902 adults in California. Physical inactivity was associated with perceived
stress and depression. The effect was magnified by job stress.
Tercyak et al.
65
reported on the relationship of health demoting behaviors
(smoking, non-adherence to sun protection, and physical activity) to depression in a
sample of 75 cancer surviving adolescents aged 11-21 years. They found that insufficient
10
physical activity was second to inadequate sun protection in behaviors and that number of
detrimental behaviors was significantly related to stresses as measured by the interaction
of depression score (using CES-D as a measure of for personal stress) and child-parent
conflict (using the problems subscale of the Barnes and Olson Parent-Adolescent
Communication Scale) as a measure for family stress. In these cross-sectional measure,
causality can not yet be assessed, but it is worth looking at, particularly in light of the
evidence that physical activity can decrease stress and associated negative affect.
7, 20, 21, 45,
50

Stress & Physical Activity
Physical activity can improve how adolescents view themselves, something that
may be damaged with obesity. Daley et al.
14
reported on randomized controlled trial of 81
obese and morbidly obese adolescents who were randomized into either a treatment
group (exercise therapy), or one of two placebo groups (equal-contact or usual care).
Participants ranged in age from 11-16 years, 44.4% were male, and most (82.7%) were
Caucasian (9.9% were Black and 7.4% were South Asian). The exercise treatment
focused on aerobic exercise performed at a moderate intensity. The equal contact group
spent equal time stretching and doing light conditioning. The treatment and equal contact
groups met three times a week for eight weeks of one-on-one training. Measures of self-
perceptions of worth (from Harter’s Self Perception Profile for Adolescents), depression
(Children’s Depression Inventory), and affect were collected in addition to
anthropometric and fitness levels and participation at baseline, after 8 weeks, and also at
14 and 28 weeks from start of study. After controlling for baseline scores, there were
significant differences found in evaluations of physical self-worth between exercise
11
therapy group and usual care at 8, 14, and 28 weeks (all p-values < .05), and between the
equal-contact and usual care group at 8 weeks. There were also difference in global self-
worth between exercise treatment and equal contact at 14 and 28 weeks. There were no
differences in BMI between groups at any time point. These findings indicated that self-
worth is benefited by aerobic exercise, and that these are not necessarily due to physical
changes.
The use of Mind-body therapies in adolescents for stress reduction
Given these mechanisms by which stress may influence obesity, it is possible that
reductions in stress could lead to reductions in obesity. Mind-body therapies, including
meditation have been shown to be efficacious for treating coronary artery disease,
headaches, insomnia, incontinence, chronic low back pain, cancer treatment,
hypertension, and arthritis
2
. While most studies have been completed with adult
participants, studies have shown that mind-body treatments can be successful in
adolescents. Pawlow and Jones
57
explored the psychological and physical effects of a
one-hour progressive muscle relaxation intervention. Participants were undergraduate
students matched for age and gender. Forty-one participants received an individual 1-
hour long relaxation session that was standardized across participants, and 14 matched
controls spent an hour sitting quietly in a laboratory. There were significant within-group
decreases in self-reported anxiety and perceived stress, as well as significant increases in
reported relaxation among the experimental participants, but not in control participants.
In addition, there were significant between group differences in pre-to-post anxiety and
stress between groups. Salivary cortisol also decreased significantly within the
experimental group, though not in the control group. There was a significant difference in
12
pre-to-post salivary cortisol change between groups. That study demonstrates that acute
effects of progressive relaxation, such as that involved in the Interactive Guitide Imagery
(IGI) sessions used in that study, are efficacious. The effects for self-reported measures
were very large (effect sizes for acute effects in the intervention group ranged from 3.6
to 14.1), whereas the effect for salivary cortisol was small (effect size = 0.3).
In randomized controlled trials, Transcendental Meditation, which shares many of
the same characteristics as IGI, has been shown to lower ambulatory blood pressure in
African American adolescents over 24 hours
4
and during stressful situations
3
. Gordon et
al.
34
conducted a study in which mind-body skills including meditation, biofeedback, art
therapy, autogenic training, guided imagery, movement and breathing techniques were
taught to 139 teenagers aged 12 to 19 years in a Kosovo high school. There was large
decreases in Post-Traumatic Stress Disorder from pre-test to post-test, 6 weeks later
(effect sizes ranged from 0.6 to 2.4), which were maintained at follow-up a year later.
This study did not include a control group for ethical reasons, so it is possible that the
large decreases were related to time passing since the war’s end. Wall
70
reported on
qualitative reports of middle school children (ages 11-13) who participated in a tai-chi
and mindfulness based stress reduction program. The children reported being more
relaxed and calm, sleeping better, being more self-aware, and being less reactive.
Relaxation has been used as a control group feature for cognitive-behavioral
therapy interventions of obesity in children, however its value as a control group is
questionable due to lack of significant between groups findings. Duffy and Spence (1993)
found no differences for cognitive-behavioral therapy vs. relaxation in 27 overweight 7-
13 year olds who went through eight treatment/relaxation sessions. They found that both
13
groups decreased in percent of overweight participants as well as the number of high-risk
foods eaten by participants, but that there were not differences between groups in these
declines.
19,72

Warshberger et al.
50
reported similar results on a randomized controlled
trial of obese 9-19 year olds in Germany. All participants completed a 6-week in-patient
visit at a rehabilitation hospital where they participated in (non-specified) exercise and a
reduced-calorie diet. In addition, participants were randomized to a cognitive-behavioral
treatment group or a control group who underwent muscle relaxation. The decline in
percentage of overweight participants in the control group was not significantly different
than the treatment group at the end of 6 weeks, or at 6 months and 1 year follow-up. Both
groups continued good progress after leaving the program. Low power could not be
blamed for this lack of significant findings, as it could with Duffy and Spence
19, 72

as
there were 121 children in the intervention group and 76 controls. These studies indicate
that relaxation may be as effective as cognitive-behavioral therapy for treating obesity in
children.
The study population: Stress and Obesity in Adolescence
Adolescence is a very stressful time for children, and studies show that it is
becoming more and more stressful.
68
For this reason, it is a key time in the lifespan for
staging interventions that target to reduce stress, and teach adolescents to replace
unhealthy behaviors and habits with healthy ones. In addition, adolescence is a perfect
time to try to develop healthy behaviors since at the time of adolescence, children gain
freedom to make more food choices, and to decide how much physical activity they get.
However, many adolescents come to this time ill prepared for making healthy choices.
There are some benefits to focusing weight interventions in adolescents rather than in
14
adults. Epstein et al.
27
point out that treating obesity children can be easier than treating
obesity in adults. They review many obesity interventions in children and suggest that
found that:
“it may be easier to mobilize support through families for obese children than for
obese adults; obese children also generally have not had the unhealthy eating or
activity patterns as long as obese adults. Furthermore, instead of shrinking
adipose cells, treatment at an early age prevents the development of excess
adipose cells” (p. 555)

This review also points to the importance of addressing the complex behavior
changes required to battle childhood obesity individualistically. The need to address the
psychosocial determinants of obesity is also highlighted in the review by Summerbel et al
(2006).
64

One mind-body technique that may be useful for stress reductions in adolescence
is Interactive Guided Imagery (IGI). IGI is a mind-body health modality involving
creating an association between a relaxed physiological state and individually specific
images.
26, 51, 60
The process combines the well-known psychological modality of classical
conditioning with the effectiveness of meditative stress reduction and progressive muscle
relaxation, both of which have been shown to reduce stress.
26, 51, 53, 60
Participants learn to
associate the experience of sitting calmly in a relaxed state with an image of their
choosing that represents reduced stress and that has subjective, individualized relevance
for them. Once the conditioned association has been made, participants learn to access
the image (and hence the associated relaxed state) during times of stress. Once, achieved,
the relaxed state reduces stress, both psychological and physiological. This state of
reduced stress may cascade down into a series of health benefits through the same HPA
15
and behavioral mechanisms discussed above (Figure 1). In this study, we will focus on
psychological and physiological measures of stress and the effect of IGI on them.
How IGI works to decrease stress through working on the mechanisms of stress
IGI decrease stress by first having the participants experience the natural pairing
of the deep breathing (unconditioned stimulus) with the resulting relaxation
(unconditioned response). This stimulus-response bond is formed through series of
exercises focused on teaching individuals to experience meditative relaxation through
deep breathing exercises, along with progressive muscle relaxation. This type of
relaxation has been shown to decrease stress and improve a number of health conditions
in adults
2
including hypertension
44
, epilepsy
59
, weight loss
62
, and anxiety
41, 61
.
Once the individuals have achieved a relaxed state, they are guided to imagine a
stimulus image that is peaceful and relaxing to them. These stimuli are unique to each
individual, and are chosen to enhance the state of relaxation by being a place or thing that
is perfectly safe and relaxing for the individual. This image is the conditioned stimulus.
Consistent practice in which an image is linked with a feeling of relaxation, creates a
bond between the image (conditioned stimulus) and relaxation (now the conditioned
response). Once the conditioned bond between the relaxed state and the image is made,
the image becomes a stimulus for the relaxed state. This new conditioned stimulus-
conditioned response bond allows participants to experience relaxation by summoning
their personalized image and allows the individual to feel more relaxed, even in a
stressful situation, by imagining the stimulus image. In addition to being useful for
acutely stressful times, practicing relaxation through visualizing the image regularly may
be able to reduce the effects of chronic stress. IGI should impact both mechanisms by
16
which stress leads to obesity. First, IGI should calm the nervous system, which is
measurable by changes in cortisol, the product of the HPA axis. Also, participants should
experience psychological calming, measured in decreases in negative affectivity such as
anxiety and worry.
Research Aims
The purpose of this pilot study was to examine whether a novel intervention
protocol that used Interactive Guided Imagery (IGI), could lower stress in overweight,
urban, Latino adolescents, a population that experiences high levels of chronic stress due
to racial discrimination, low SES, and is particularly at risk for obesity, metabolic
syndrome, and type 2 diabetes
5, 16, 31, 33
,
36, 67, 74
. IGI impacts both of the mechanisms by
which stress contributes to obesity, thus the outcome measures represent the HPA axis
and psychological stress. In this pilot study, the stress reduction technique of Interactive
Guided Imagery (IGI) was explored as a stress-reduction intervention. For the purpose of
this paper, the focus will be on measuring the stress-reducing impact of IGI on the HPA
and behavioral axes.
Hypotheses
Hypothesis 1: There will be an acute reduction in response to IGI session in stress
as measured by within session (pre-to-post) change in salivary cortisol and Visual Analog
Scale.
Hypothesis 2: There will be longitudinal declines in stress in response to IGI
sessions across the 4 weeks seen in lower pre-intervention stress levels, and larger pre-to-
post intervention declines in response to IGI sessions.
17
Methods
Sample and Study design
This study is a randomized controlled trial consisting of two groups: Interactive
Guided Imagery (IGI) and Control. To be eligible for this study, participants needed to be
English speaking adolescent boys and girls aged 14-16 years, who were in the 9th grade
or higher. They had to have Latino heritage assessed by parental self-report of all four
biological grandparents being of Latino heritage. They were required to have a BMI
percentile greater than the 95
th
percentile for age and sex using CDC 2000 criteria.
10

Participants were excluded if they participated in any weight loss program within 6
months, had a serious chronic illness, had medical condition or were taking medication
that would effect body composition or insulin sensitivity/secretion, had participated
regularly in any mind-body stress reduction and relation practices in the past, had a
clinically diagnosed psychiatric or eating disorder, or were cognitively or
language/hearing impaired.
Measures
Anthropometric and Body Composition Measurements
Height and weight were measured in triplicate using a beam medical scale and
wall-mounted stadiometer, to the nearest 0.1 kg and 0.1 cm, respectively. BMI percentile
was calculated by using the CDC’s 2000 criteria for BMI for age and gender
10
. Tanner
staging was performed by a licensed pediatric care provider (physician or physician
assistant) using established guidelines.
47, 48

18
Interactive Guided Imagery Intervention
The Interactive Guided Imagery (IGI) intervention used in this study consisted of
four 45-minute modules based on standard imagery techniques, coupled with data from
focus groups. Participants attended one session a week for four weeks. The techniques
were introduced gradually, building on previous sessions. Session 1 included focused
diaphragmatic breathing and the principles behind imagery. In Session 2, progressive
muscle relaxation was added to the focused breathing work. In Session 3, safe place
imagery was added. Safe place imagery involves an exploration of safe, comfortable
place specific to the participant through imagining he or she was there. In the final
session, conditioned relaxation, a technique which allows participants to quickly and
easily access an image that is relaxing during daily activity, was added to the intervention
time.
Salivary Cortisol
Salivary cortisol correlates with free (unbound) plasma cortisol and is thus a good
indicator of the physiologically active form of the hormone, and is an indicator of HPA
axis activity. Sampling of cortisol was obtained using the Salivette system in which a dry
cotton swab is placed in the mouth for 2 minutes to passively absorb saliva. This
procedure yields approximately 1 mL of saliva. The wet swabs are placed in the
refrigerator until transferred to the lab for analyses. To allow for the possibility that any
changes observed in salivary cortiosol is due to diurnal variation, control participants also
took the salivary cortiosol measures at the same time in the afternoon at home and then
placed the samples in the freezer. Research staff phoned participants to assure that the
timing coincided with that of the GI group. At home samples were picked up the same
19
evening or following morning by study personnel. All salivettes were kept frozen at -70
C until processed. They were placed in a centrifuge (2500 RPM for 10 minutes at -4—8
C) and then frozen at -70 C until assayed. Samples were processed by immunomometric
assay on Tosoh AIA 600 II analyzer in General Clinical Research Center Core Lab.
Visual Analog Scale
Psychological stress was measured only in the IGI group pre and post each IGI
session using the Visual Analog Scale (VAS). The VAS was created using six items of
the Profile of Mood States-Adolescent (POMS-A) tension subscale
66
following the
example of Gattuso et al.
29
Participants rated how much they felt the following emotions:
stressed, panicky, anxious, worried, nervous, and calm on a line that is 100 mm long that
is marked “not at all” on the left and “extremely” on the right (Appendix A). Because
there are no defined categories, the VAS can be very sensitive to small differences in
mood. Responses are scored on their length, measured in mm, by a research assistant
blinded to subject number and week of session. A sum of all items created a total score.
Scale reliability analyses showed that the anxious and serene items were not well
correlated with the others, and were dropped from the total score analyses. The remaining
items were summed for a total score that relates to state psychological distress, and has an
internal reliability coefficient (α) ranging from .52 - .99 (Mean = .83 SD = .20) across
the 4 sessions. This is similar to the reliability reported by Gattuso et al.
29
who found
internal reliability at pre-intervention, post-intervention, and post-endoscopy procedure to
be .83, .75, and 86, respectively. The reliability of this scale is much better for post-
session measures than pre-session measures. Pre-session reliabilities for sessions 1
20
through 4 are: .52, .76, .56, .99. Post-session reliabilities for sessions 1 through 4 are: .84,
.99, .98, .96.
Procedure
Participants in the IGI group received a weekly 45-minute IGI session for four
consecutive weeks. Imagery sessions were conducted separately for each participant by
an Interactive Guided Imagery
TM
practitioner who had been certified by the Academy for
Guided Imagery. Only one IGI practitioner was used in these sessions. At the beginning
of each session, participants completed VAS surveys and provided a salivary cortisol
sample. Then the IGI session began with relaxed breathing and the week’s techniques
were added as described above. After the session, a second set of VAS surveys and
salivary cortisol samples were collected. There was 100% compliance in session
attendance. In between the sessions, participants were asked to practice imagery at home
for 10 minutes, twice a day. Practice logs were given to participants to record the times of
their practice as well as a description of the imagery practice. Participants in the Control
group received no treatment.
Data Analysis
Comparison of age, tanner stage, and BMI percentile in controls and IGI groups
were performed to assure that randomization was balanced. Any notable differences (p <
.10, due to small sample sizes) were controlled for in further group comparative analyses.
This study examined two different types of change: acute response within IGI
sessions, and change over the course of the study in acute response to IGI. Acute changes
in stress outcome variables (salivary cortisol and VAS) were compared pre- and post-test
21
using paired t-tests for each session. For salivary cortisol, which was measured in both
groups, comparison of the acute changes in each group was made using multiple linear
regression analysis so as to control for Tanner stage in the groups. VAS was only
completed by the IGI group, so there was no group comparison of acute response for the
psychological stress measure.
Repeated Measures Generalized Linear Modeling was used to evaluate trends in
acute response of salivary cortisol to IGI over time. Because of the novelty of the
intervention at the first session, participants were more likely to be nervous and the
measurements may not be reflective of longitudinal trends. Therefore, the repeated
measures models only included visits 2 through 4. Interactions of longitudinal trends and
group indicate whether the longitudinal response is different for IGI versus controls in
Salivary Cortisol. All statistical tests were performed using SPSS (Version 11.0)
1
.
As this is a pilot study, focused on finding effect sizes to calculate power with. As
such, no sample size calculations were performed beforehand. Given the current sample
size of 6 per group, using a power of .80, an effect size of 1.80 would be needed to find a
significant difference at α = .05; an effect size of 1.55 would be detectable at α = .10.
These very large effects are unlikely. Because of this, p-values are of limited use in
making statistical inference in this study and for all analyses. Thus, α < 0.10 was used as
an indicator of statistical significance and effect sizes and correlations were also used to
assess potentially important biological relevance that is not captured in a statistical test.
The following guidelines suggested by Cohen (1988)
12
will be used to determine the
strength of effects: small = .2, medium = .5, large = .7.
22
Results
Participant Characteristics
The mean age was 16.1 years (SD = 0.6) in the IGI group and 15.8 (SD = 1.12) in
the control group (p = 0.58). BMI percentile was 98.5 (SD = 1.1) in the IGI group and
97.1 (2.2) in the control group (p = 0.22). Tanner stage for participants ranged from 3
through 5. As can be seen in
Figure 2 while the intervention
group included 2 participants in
Tanner stage 3, 4, & 5, the
intervention group was comprised
of 5 participants in Tanner stage 5
and 1 in Tanner stage 6. Due to
this difference in tanner stage (p =
0.07), Tanner stage was controlled
for in all between-group
comparisons.
Correlation of Salivary cortisol and VAS
Correlation of the two stress measures (Table 1) were generally not very strong
and varied greatly in magnitude and even direction. While it would be expected that all
correlations would be negative (high salivary cortisol associated with lower reported
stress), this association did not necessarily hold up. While these correlations are only
available for the IGI group, it does not appear that the physical and psychological stress
measures are consistently related.
Figure 2. Tanner Stage for IGI and Control
Groups (p = .07)
Tanner stage 5 Tanner stage 4 Tanner stage 3
N
6
5
4
3
2
1
0
IGI
Control

23

Stress Reduction Pre-to-Post
Session: Acute Effects of
Interactive Guided Imagery
Acute Decline in Stress Within Groups for Sessions 1-4
Table 2 reports the stress outcome variables pre-and post intervention for the two
groups at each session. There were significant declines in Salivary Cortisol within
sessions 2, 3, and 4 for the IGI group. There were no significant changes in Control group
in Salivary Cortisol within any of the sessions, though there were small declines in
salivary cortisol values. Measures of
effect size of change within session were
moderate to very high in the IGI group
(range .72 to 1.4). In all but one session,
there was a mean decrease of 1 standard
deviation or more in Salivary Cortisol
from pre- to post-IGI session (Figure 3).
Effect sizes were small to moderate within
the Control group (ranging from .04 to
.69), indicating that some of the changes in Salivary Cortisol seen in the IGI group may
attributable to diurnal variation.
Table 1. Correlation of Salivary Cortisol with VAS
at each session for IGI participants.
Pre-Session Post-Session
Week 1 -0.58 0.02
Week 2 -0.31 -0.31
Week 3 0.36 0.52
Week 4 -0.87** -0.75*
*p < .10; **p < .05
Figure 3. Effect sizes of Salivary Cortisol
Acute Response Across Sessions for
Interactive Guided Imagery (IGI) and
Control Groups

Table 2. Acute Stress Measures Pre- & Post-IGI Session
Stress Outcome Interactive Guided Imagery Control
Pre-Session Post-Session E.S. Pre-Session Post-Session E.S.
Salivary Cortisol
1 0.83 + 0.17 0.64 + 0.19 1.05 0.56 + 0.29 0.52 + 0.25 0.16
2 0.66 + 0.26 0.52 + 0.12 * 0.72 0.68 + 0.25 0.55 + 0.20 0.54
3 0.66 + 0.16 0.48 + 0.10*** 1.40 0.50 + 0.16 0.40 + 0.14 0.69
4 0.61 + 0.19 0.44 + 0.16*** 0.99 0.52 + 0.31 0.50 + 0.28 0.04
VAS
1 62.0 + 41.2 19.2 + 15.8* 1.50
2 31.5 + 40.4 15.3 + 21.5 0.52
3 35.2 + 29.0 14.3 + 16.3* 0.92
4 26.0 + 39.5 15.8 + 25.1 0.31
24

When comparing acute salivary cortisol decline within each session between the
IGI and Control group, controlling for Tanner stage, there was a treatment effect (p =
.099) in the final session only. However, there was an increasing amount of variability in
acute response accounted for by treatment group in the latter sessions: R
2
attributable to
treatment group, after controlling for Tanner, for Sessions 1-4 was: .076, .052, .269, .273,
respectively.
VAS scores, which measure psychological stress state, also declined during the
IGI sessions. These measures were only taken in the IGI group. There were significant
declines in VAS in Session 1 and 3 (Table 2). There was less consistency in effect than
with salivary cortisol. The largest effect was seen at the first session, in which there was a
decline of 1.5 standard deviations. However, the participants also had much higher pre-
session VAS scores at this first session (M = 62.0, SD = 41.2) than in subsequent sessions
(means 31.5, 35.2, & 26.0 for sessions 2, 3, & 4, respectively). It is possible that the
novelty of the experience at the first session caused extra psychological stress that was
alleviated in subsequent sessions after the participants knew what to expect. Post-IGI
session means were all very similar, as can be seen in Table 2. Unfortunately, no group
comparisons were possible for VAS.
Correlation of Initial Stress and Acute Stress Decline Within Session
The correlations of stress measures at baseline and acute decline are reported in
Figures 4 and 5. All correlations were negative indicating that the higher the initial level
of stress, the greater the decline in salivary cortisol (Figure 4) and VAS (Figure 5) seen.
Correlations for salivary cortisol in the IGI group were generally very high across the
25
visits. This negative correlation is also seen in Controls (for Salivary Cortisol), though
the association is much stronger with the IGI group. However, there is not a statistically
significant difference in the size of these correlations between groups (all p’s > .05) due
to the small sample size.
26

Figure 4. Correlation of Pre-Session Salivary
Cortisol to Change in Cortisol
IGI Treatment Group
Pre-Session
1.2 1.0 .8 .6 .4 .2
Acute Response P re->Post Session
.4
.2
-.0
-.2
-.4
-.6
Session 4
r = -.56
Session 3
r = -.87**
Session 2
r = -.95***
Session 1
r = -.80*

Control Group
Pre-Session
1.2 1.0 .8 .6 .4 .2
Acute Response P re->Post Session
.4
.2
-.0
-.2
-.4
-.6
Session 4
r = -.56
Session 3
r = -.60
Session 2
r = -.61
Session 1
r = -.60

* p < .10; **p < .05; ***p < .01

27

Figure 5 Correlation of Pre-Session VAS to Change in VAS
IGI Treatment Group
Pre-Session
120.0 100.0 80.0 60.0 40.0 20.0 0.0 -20.0
Acute Response P re->Post Session
20.0
0.0
-20.0
-40.0
-60.0
-80.0
-100.0
Session 4
r = -.92***
Session 3
r = -.83**
Session 2
r = -.92***
Session 1
r = -.93***

* p < .10; **p < .05; ***p < .01

Longitudinal Trends in Stress Declines Visits 2-4
Trends in Pre-Session Stress
There was as significant linear visit-by-group trend in pre-intervention salivary
cortisol from sessions 2 through 4 (p = .077), controlling for Tanner stage. Figure 6
shows the estimated marginal means for pre-session salivary cortisol for groups. As can
be seen in these predicted values, there is much stability in the IGI group, while the
Control group fluctuates more from week to week.
28

Figure 6. Salivary Cortisol Estimated Marginal Means (+ SE)
for Pre-Session For Sessions 2-4

There was no significant trends in VAS from sessions two through four (p =
0.18). As can be seen in Figure 7, which shows the estimated marginal means across all
four sessions, the VAS scores for these latter sessions were much smaller than in the first
week. No group
comparison was
possible.
Figure 7. VAS Estimated Marginal Means for Pre-Session
and Acute Decline

29
Trends in Acute Stress Reduction
The increases in the amount of variability explained attributable to IGI across the
sessions provides some support for the hypothesis of a larger effect of IGI over time.
When trends were tested, there was a significant linear effect of visit by group (p = 0.10).
Figure 8 shows the estimated marginal means for the IGI and Control groups in acute
salivary cortisol change. As can be seen, the groups have opposite trends for salivary
cortisol change. While the IGI group experienced greater changes from sessions 2
through 4, the control group has lesser change and by the last session had no change.

There was no significant trend in acute VAS pre-to-post session change for the
IGI group (all contrast p's > .10). Figure 7 shows the estimate marginal means for VAS
change. After the first session, participants starting VAS scores were so low that they had
very little change to make.
Figure 8. Salivary Cortisol Estimated Marginal Means (+ SE)
for Acute Decline Over 4 Weeks

30
Discussion
There were moderate to large acute decreases in physiological stress as measured
by salivary cortisol, a measure of HPA axis activity attributable to IGI cross-sectionally.
These effects were seen in each of the four sessions, and were reasonably consistent
across sessions, indicating that the effectiveness of IGI on HPA axis that was noticeable
immediately and further, is maintained over four weeks. There were also decreases in
reported psychological stress as measured by VAS in the IGI group, though these results
were less consistent. These results support Hypothesis 1 which predicted acute stress
reduction within sessions. Hypothesis 2, which predicted that the stress-reducing effects,
as measured by trends in baseline stress and acute declines would increase over the four
weeks was supported by acute declines in salivary cortisol from session 2 through 4.
While there was a group difference in pre-intervention salivary cortisol, these levels did
not decrease over the study. For VAS, there was a longitudinal trend. It is difficult to
come to conclusions about these trends after only a four week study. In addition, the
progressive nature of the program means that the treatment was different across the four
weeks, complicating interpretation. However, these results suggest that IGI is beneficial
to HPA axis activation. A longer study may be required to understand this pattern more.
However, these pilot data do show that the effectiveness of IGI can be seen immediately
in this population.
One of the interesting findings was the poor and inconsistent association between
salivary cortisol and the VAS. This may be due to there being more noise in the VAS
data, or the participants becoming bored with filling out the questionnaires. It also could
mean that there is a disconnection between how stressful people report feeling and the
31
excitation of the HPA axis. This finding is not unique, however. Putterman & Linden
26
,
who examined salivary cortisol and cognitive dietary restraint in 170 young women also
found that there was no significant relationship between awakening cortisol (r = .01) or
cortisol 6-8 hours later (r = .12) and self-reported perceived stress. They suggest that the
construct of perceived stress may not be related to HPA axis activation, though constructs
of self-efficacy were. Since self-efficacy was not measured in this sample, this is not
something we can test here, though there is potential for IGI to improve self-efficacy,
something that may be useful for future research.
Compliance with the treatment and participant evaluations of the program
supports this conclusion. There was 100% compliance for the guided imagery sessions;
no participant missed any of the sessions. Post-intervention evaluations by participants
were very positive. Comments about the study at the end include:
“Cool”
“It was really relaxing”
“It felt good – took the tension away”
“I was able to concentrate in my math test better.”
Despite their enthusiasm about the IGI sessions, compliance to the at home
portion of the intervention was poor. The protocol called for participants to practice IGI
at home two times a day for 5-10 minutes. As can be seen in Figure 9, which shows the
reported practicing for weeks 1-3 (week 4 being the end of the study), most participants
reported practicing a few times a week. Almost all practiced only once a day and were in
the 5-10 minute range. It is possible that more use of home practice could lead to longer-
term reductions in stress, beyond the acute reduction seen in the sessions. While IGI has a
32
positive effect on stress reduction, as measured by cortisol, these are such short-term
impacts and may have limited effect on the HPA axis. Thus, in the future, focusing more
efforts on training participants to work on IGI at home, and structuring the home practice
to ensure compliance, should be a major goal in efforts to decrease stimulus of the HPA
Axis.
Figure 9. Number of Home Practice Days Reported Weeks 1-3

33
Results were much more impressive and consistent for salivary cortisol than for
the VAS, a psychological measure of stress. There are several possible explanations for
this lack of effect. First, it could be that the calming of the HPA axis measured by
salivary cortisol is more immediate than that measured by the VAS. It is possible that the
VAS is not sensitive enough to detect acute changes in affect. Another possibility is that
IGI does not work very well on psychological stress. This is unlikely, especially
considering the extensive evidence that meditative techniques have a positive effect on
psychological stress. Finally, it could be that the participant grew bored with the VAS
and just started to fill it out without much thought or consideration. This last explanation
is the most likely, especially given the pattern of responses over time. Participants started
marking the far end of the scales consistently down all item. This includes items that we
did not include in these analyses due to lack of inter item reliability that was reverse
coded. Given the poor correlation of salivary cortisol, a physiological measure, and the
VAS, a subjective measure, the results from the salivary cortisol are more reliable.
Further, given the lack of a comparison group for the VAS, these results should be taken
in context. Any future use of a psychological tool should include a control group
comparator.
This pilot study indicates that this type of intervention is both feasible and
effective in an adolescent, Latino population. The positive reports of the experience by
participants, as well as the perfect attendance record speaks of an intervention that is fun
and that participants even looked forward to. The idea that an obesity intervention could
reduce stress, instead of increasing it (as many who have embarked on a new diet and/or
exercise program can tell you) is rather novel and suggests exciting potential for the
34
future. Further, the immediate response in stress reduction indicates that this intervention
may be useful even in short-term interventions.
This study provides evidence that it is possible to decrease activity of the HPA
axis through IGI. This is just one part of the proposed Stress-> Obesity model proposed.
Whether this reduction in stress can then be seen in reduction of obesity is the work of
the future. Also, while this pilot study encompassed 4 weeks of IGI targeted on stress
reduction, there are other foci of IGI that could be included, such as targeting images to
be mindful of hunger and associating positive feelings with physical activity. IGI is a
flexible method that can target specific behaviors and has the potential to be used alone,
or to add another dimension to obesity prevention and treatment programs for a more
integrative approach.
Strengths of the study
This novel study provided a pleasant and effective intervention to reductions in
stress in overweight Latino adolescents. The treatment was relaxing, enjoyable, and non-
invasive. Response was immediate and continued in the IGI group.
Limitations of the study
The main limitation of this study is the limited sample size. However, this project
was a pilot study with the aim at determining feasibility and effect sizes. Both of these
goals were realized, though results for VAS psychological stress were limited. The small
sample size also limited the testing of Tanner stage as an effect modifier, and not just a
covariate. Another weakness was that the control group did not complete any measure of
psychological stress at home. As their salivary cortisol showed a decrease during the
times of the intervention, it is also possible that this was an accompanying decrease in
35
psychological stress as the participants came home from school and relaxed in their home
environment. Along these lines, while this study did measure the HPA axis, which has
been shown to be one path to obesity, the behavioral actions that lead to obesity (food
intake and physical activity) were not measured in this study, and so this part of the
model remains hypothetical and not yet demonstrated. The control group may not be
comparable to the intervention group because they did not receive the same
individualized attention that the IGI group did. It could be argued that some of the
effectiveness of IGI may be due to participants receiving special attention by a friendly
and caring adult.
Future Directions
The 4-week guided imagery program is currently being tested as an expanded 12
week program which will add several new components to the current 4 week stress
reduction that focus on the behavioral axis that links stress and obesity. Another
important component is a control group that receives the same amount of individual
attention while working on a project. This will also allow study personnel to measure
psychological stress and control the environment of the control group much better. This
work is currently progressing.
Conclusion
In conclusion, IGI was demonstrated feasible and effective for the acute reduction
in stress in overweight Latino adolescents. These effects were mostly seen in decreases in
salivary cortisol, a measure of the HPA axis. Whether this stress reduction will lead to
decreases in obesity and the attending health implications remains to be demonstrated.
36
Bibliography
1. SPSS Mac OS X Version. In. 11.0 ed; 2005.
2. Astin JA, Shapiro SL, Eisenberg DM, Forys K. Mind-body medicine: State of the
Science, Implications for Practice. J Am Board Fam Pract 2003;16(2):131-147.
3. Barnes VA, Treiber FA, Davis H. Impact of Transcendental Meditation on
cardiovascular function at rest and during acute stress in adolescents with hihg normal
blood pressure. Journal of Psychosomatic Research 2001;51:597-605.
4. Barnes VA, Treiber Fa, Johnson MH. Impact of transcendental meditation on
ambulatory blood pressure in Afreican-American Adolescents. . American Journal of
Hypertension 2004;17:366-369.
5. Baum A, Garofalo JP, Yali AM. Socioeconomic status and chronic stress. Does
stress account for SES effects on health? Annals of the New York Academy of Sciences
1999;896:131-44.
6. Bjorntorp P, Rosmond R. Neuroendocrine abnormalities in visceral obesity.
International Journal of Obesity & Related Metabolic Disorders: Journal of the
International Association for the Study of Obesity 2000;24 Suppl 2:S80-5.
7. Blumenthal JA, Babyak MA, Moore KA, Craighead WE, Herman S, Khatri P,
Waugh R, Napolitano MA, Forman LM, Appelbaum M, Doraiswamy PM, Krishnan KR.
Effects of exercise training on older patients with major depression. Archives of Internal
Medicine 1999;159(19):2349-56.
8. Cartwright M, Wardle J, Steggles N, Simon AE, Croker H, Jarvis MJ. Stress and
dietary practices in adolescents. Health Psychology 2003;22(4):362-9.
9. Charmandari E, Kino T, Souvatzoglou E, Chrousos GP. Pediatric stress: hormonal
mediators and human development. Hormone Research 2003;59(4):161-79.
10. Charts CfDCaPCg. Centers for Disease Control and Prevention: CDC growth
Charts. . In: U.S. Department of Health and Human Services CfDCaP, National Center
for Health Statistics, Atlanta, GA, editor.: U.S. Publ. ; 2000.
11. Chrousos GP. The role of stress and the hypothalamic-pituitary-adrenal axis in the
pathogenesis of the metabolic syndrome: neuro-endocrine and target tissue-related
causes. International Journal of Obesity & Related Metabolic Disorders: Journal of the
International Association for the Study of Obesity 2000;24 Suppl 2:S50-5.
12. Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale,
NJ: Lawrence Earlbaum Assoc.; 1988.
37
13. Cruz ML, Weigensberg MJ, Huang TTK, Ball G, Shaibi GQ, Goran MI. The
metabolic syndrome in overweight Hispanic youth and the role of insulin sensitivity.
Journal of Clinical Endocrinology & Metabolism 2004;89(1):108-13.
14. Daley AJ, Copeland RJ, Wright NP, Roalfe A, Wales JKH. Exercise therapy as a
treatment for psychol pathologic conditions in obese and morbidly obese a dole scents: A
randomized, controlled trial. Pediatrics 2006;118(5):2126-2134.
15. Dallman MF, Pecoraro N, Akana SF, la Fleur SE, Gomez F, Houshyar H, Bell
ME, Bhatnagar S, Laugero KD, Manolo S. Chronic stress and obesity: An new view of
"comfort food." Proceedings of the National Academy of Sciences of the United States
of America 2003;100(20):11696-11701.
16. De Spiegelaere M, Dramaix M, Hennart P. The influence of socioeconomic status
on the incidence and evolution of obesity during early adolescence. International Journal
of Obesity & Related Metabolic Disorders: Journal of the International Association for
the Study of Obesity 1998;22(3):268-74.
17. Dietz WH. The role of lifestyle in health: the epidemiology and consequences of
inactivity. Proceedings of the Nutrition Society 1996;55(3):829-40.
18. Dietz WH. Health consequences of obesity in youth: childhood predictors of adult
disease. Pediatrics 1998;101(3 Pt 2):518-25.
19. Duffy G, Spence SH. The effectiveness of cognitive self-management as an
adjunct to a behavioural intervention for childhood obesity: a research note. Journal of
Child Psychology & Psychiatry & Allied Disciplines 1993;34(6):1043-50.
20. Dunn AL, Trivedi MH, Kampert JB, Clark CG, Chambliss HO. Exercise
treatment for depression: efficacy and dose response.[see comment]. American Journal of
Preventive Medicine 2005;28(1):1-8.
21. Dunn AL, Trivedi MH, O'Neal HA. Physical activity dose-response effects on
outcomes of depression and anxiety. Medicine & Science in Sports & Exercise 2001;33(6
Suppl):S587-97; discussion 609-10.
22. Ebbeling CB, Pawlak DB, Ludwig DS. Childhood obesity: public-health crisis,
common sense cure. Lancet 2002;360(9331):473-82.
23. Eisenmann JC. Secular trends in variables associated with the metabolic
syndrome of North American children and adolescents: a review and synthesis. American
Journal of Human Biology 2003;15(6):786-94.
24. Eisenmann JC. Insight into the causes of the recent secular trend in pediatric
obesity: Common sense does not always prevail for complex, multi-factorial phenotypes.
Preventive Medicine 2006;42(5):329-335.
38
25. Epel ES, McEwen B, Seeman T, Matthews K, Castellazzo G, Brownell KD, Bell
J, Ickovics JR. Stress and body shape: stress-induced cortisol secretion is consistently
greater among women with central fat. Psychosomatic Medicine 2000;62(5):623-32.
26. Epstein G. Healing Visualizations: Creating health through imagery. New York:
Bantam Books; 1989.
27. Epstein LH, Myers MD, Raynor HA, Saelens BE. Treatment of pediatric obesity.
Pediatrics 1998;101(3 Pt 2):554-70.
28. Fulkerson JA, Sherwood NE, Perry CL, Neumark-Sztainer D, Story M.
Depressive symptoms and adolescent eating and health behaviors: a multifaceted view in
a population-based sample. Preventive Medicine 2004;38(6):865-75.
29. Gattuso SM, Litt MD, Fitzgerald TE. Coping with gastrointestinal endoscopy:
self-efficacy enhancement and coping style. Journal of Consulting & Clinical Psychology
1992;60(1):133-9.
30. Gibson EL. Emotional influences on food choice: Sensory, physiological and
psychological pathways. Physiology and Behavior 2006;89:53-61.
31. Goodman E, Slap GB, Huang B. The public health impact of socioeconomic
status on adolescent depression and obesity. American Journal of Public Health
2003;93(11):1844-50.
32. Goran MI, Ball GDC, Cruz ML. Obesity and risk of type 2 diabetes and
cardiovascular disease in children and adolescents. Journal of Clinical Endocrinology &
Metabolism 2003;88(4):1417-27.
33. Goran MI, Bergman RN, Avila Q, Watkins M, Ball GDC, Shaibi GQ,
Weigensberg MJ, Cruz ML. Impaired glucose tolerance and reduced beta-cell function in
overweight Latino children with a positive family history for type 2 diabetes. Journal of
Clinical Endocrinology & Metabolism 2004;89(1):207-12.
34. Gordon JS, Staples JK, Blyta A, Bytyqi M. Treatment of posttraumatic stress
disorder in postwar Kosovo high school students using mind-body skills groups: A pilot
study. Journal of Traumatic Stress 2004;17(2):143-147.
35. Greeno CG, Wing RR. Stress-induced eating. Psychological Bulletin
1994;115(3):444-64.
36. Haas JS, Lee LB, Kaplan CP, Sonneborn D, Phillips KA, Liang S-Y. The
association of race, socioeconomic status, and health insurance status with the prevalence
of overweight among children and adolescents. American Journal of Public Health
2003;93(12):2105-10.
39
37. Hedley AA, Ogden CL, Johnson CL, Carroll MD, Curtin LR, Flegal KM.
Prevalence of overweight and obesity among US children, adolescents, and adults, 1999-
2002.[see comment]. JAMA 2004;291(23):2847-50.
38. Hill JO, Trowbridge FL. Childhood obesity: future directions and research
priorities. Pediatrics 1998;101(3 Pt 2):570-4.
39. Hurwitz EL. Do asthma and physical inactivity influence the associations of
personal and job stressors with perceived stress and depression? Findings from the 1998-
1999 California Work and Health Survey. Annals of Epidemiology 2003;13(5):358-68.
40. Jonides L, Buschbacher V, Barlow SE. Management of child and adolescent
obesity: psychological, emotional, and behavioral assessment. Pediatrics 2002;110(1 Pt
2):215-21.
41. Jorm AF, Christiansen H, Griffiths KM, Parslow RA, Rodgers B, Blewitt KA.
Effectiveness of complementary and self-help treatments for anxiety disorders. MJA
2004;181(7):S29-S46.
42. Kandel D, Davies M. Epidemiology of Depressive Mood in Adolescents.
Archives of General Psychiatry 1989;39:1205-1212.
43. Katz JR, Taylor NF, Goodrick S, Perry L, Yudkin JS, Coppack SW. Central
obesity, depression and the hypothalamo-pituitary-adrenal axis in men and
postmenopausal women. International Journal of Obesity & Related Metabolic Disorders:
Journal of the International Association for the Study of Obesity 2000;24(2):246-51.
44. Labarthe D, Ayala C. Nondrug interventions in hypertension prevention and
control. Cardiology Clinics 2002;20:249-263.
45. Lawlor DA, Hopker SW. The effectiveness of exercise as an intervention in the
management of depression: systematic review and meta-regression analysis of
randomised controlled trials. BMJ 2001;322(7289):763-7.
46. Macht M, Simons G. Emotions and eating in everyday life. Appetite
2000;35(1):65-71.
47. Marshall WA, Tanner JM. Variations in pattern of pubertal changes in girls.
Archives of Disease in Childhood 1969;44(235):291-303.
48. Marshall WA, Tanner JM. Variations in the pattern of pubertal changes in boys.
Archives of Disease in Childhood 1970;45(239):13-23.
49. McCann BS, Warnick GR, Knopp RH. Changes in plasma lipids and dietary
intake accompanying shifts in perceived workload and stress. Psychosomatic Medicine
1990;52(1):97-108.
40
50. Mummery K, Schofield G, Caperchione C. Physical activity dose-response effects
on mental health status in older adults. Australian & New Zealand Journal of Public
Health 2004;28(2):188-92.
51. Naparstek B. Staying Well with Guided Imagery. New York: Warner Books;
1994.
52. Oliver G, Wardle J. Perceived effects of stress on food choice. Physiology &
Behavior 1999;66(3):511-5.
53. Olness K, Gardner GG. Hypnosis and Hynotherapy in Children. 2nd ed.
Philedelphia: Grune & Stratton; 1988.
54. Opie LH, Commerford PJ, Gersh BJ. Controversies in stable coronary artery
disease. Lancet 2006;367(9504):69-78.
55. Pasquali R, Vicennati V. Activity of the hypothalamic-pituitary-adrenal axis in
different obesity phenotypes. International Journal of Obesity & Related Metabolic
Disorders: Journal of the International Association for the Study of Obesity 2000;24
Suppl 2:S47-9.
56. Pasquali R, Vicennati V, Cacciari M, Pagotto U. The hypothalamic-pituitary-
adrenal axis activity in obesity and the metabolic syndrome. Annals of the New York
Academy of Sciences 2006;1083:111-28.
57. Pawlow LA, Jones GE. The impact of abbreviated progressive muscle relaxation
on salivary cortisol and salivary immunoglobulin A (sIgA). Applied Psychophysiology &
Biofeedback 2005;30(4):375-87.
58. Putterman E, Linden W. Cognitive dietary restraint and cortisol: importance of
pervasive concerns with appearance. Appetite 2006;47(1):64-76.
59. Rajesh B, Jayachandran D, Mohandas G, Radhakrishnan K. A pilot study of a
Yoga Meditation Protocol for patients with medically refractory epilepsy. The Journal of
Alternative and Complementary Science. 2006;12(4):367-371.
60. Rossman ML. Guided Imagery for Self-Healing. 2nd ed. Novato, CA: H. J.
Kramer & New World Library; 2000.
61. Stetter F, Kupper S. Autogenic Training: A meta-analysis of clinical outcome
studies. Applied Psychophysiology and Biofeedback 2002;27(1):45-98.
62. Stradling J, Roberts D, Wilson A, Lovelock F. Controllowed trial of
hypnotherapy for weight loss in patients with obstructive sleep apnea. International
Journal of Obesity 1998;28:278-281.
41
63. Strauss RS, Pollack HA. Epidemic increase in childhood overweight, 1986-1998.
JAMA 2001;286(22):2845-8.
64. Summerbell CD, Ashton V, Campbell KJ, Edmunds L, Kelly S, Waters E.
Interventions for treating obesity in children. Cochrane Database of Systematic Reviews
2003(3):CD001872.
65. Tercyak KP, Donze JR, Prahlad S, Mosher RB, Shad AT. Multiple behavioral risk
factors among adolescent survivors of childhood cancer in the Survivor Health and
REsilience Education (SHARE) Program. Pediatric Blood Cancer 2006;47:825-830.
66. Terry PC, Lane AM, Fogarty GJ. Construct validity of the Profile of Mood States-
Adolescents for use with adults. Psychology of Sport & Exercise 2003;4:123-139.
67. Treiber F, Harshfield G, Davis H, Kapuku G, Moore D. Stress responsivity and
body fatness: links between socioeconomic status and cardiovascular risk factors in
youth. Annals of the New York Academy of Sciences 1999;896:435-8.
68. Twenge JM. The age of anxiety? Birth cohort change in anxiety and neuroticism,
1952-1993. Journal of Personality & Social Psychology 2000;79(6):1007-21.
69. Wajchenberg BL. Subcutaneous and visceral adipose tissue: their relation to the
metabolic syndrome. Endocrine Reviews 2000;21(6):697-738.
70. Wall RB. Tai Chi and mindfulness-based stress reduction in a Boston public
middle school. Journal of Pediatric Health Care 2005;19(4):230-237.
71. Wardle J, Steptoe A, Oliver G, Lipsey Z. Stress, dietary restraint and food intake.
Journal of Psychosomatic Research 2000;48(2):195-202.
72. Warschburger P, Fromme C, Petermann F, Wojtalla N, Oepen J.
Conceptualisation and evaluation of a cognitive-behavioural training programme for
children and adolescents with obesity. International Journal of Obesity & Related
Metabolic Disorders: Journal of the International Association for the Study of Obesity
2001;25 Suppl 1:S93-5.
73. Weinstein SE, Shide DJ, Rolls BJ. Changes in food intake in response to stress in
men and women: psychological factors. Appetite 1997;28(1):7-18.
74. Williams DR. Race, socioeconomic status, and health. The added effects of
racism and discrimination. Annals of the New York Academy of Sciences 1999;896:173-
88.

42

Appendix A

Abstract (if available)

Abstract Objective: This pilot study examined whether a 4 week program of Interactive Guided Imagery (IGI) could reduce physiological and psychological stress in overweight, Latino adolescents.

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Asset Metadata

Creator Lane, Christianne Joy (author)

Core Title Acute stress reduction with interactive guided imagery in overweight Latino adolescents

School Keck School of Medicine

Degree Master of Science

Degree Program Biostatistics

Publication Date 07/10/2007

Defense Date 06/28/2007

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Interactive Guided Imagery,OAI-PMH Harvest,salivary cortisol,Stress

Language English

Advisor Azen, Stanley Paul (committee chair), Berhane, Kiros (committee member), Weigensberg, Marc J. (committee member)

Creator Email clane@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-m606

Unique identifier UC1325531

Identifier etd-Lane-20070710 (filename),usctheses-m40 (legacy collection record id),usctheses-c127-517218 (legacy record id),usctheses-m606 (legacy record id)

Legacy Identifier etd-Lane-20070710.pdf

Dmrecord 517218

Document Type Thesis

Rights Lane, Christianne Joy

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Repository Name Libraries, University of Southern California

Repository Location Los Angeles, California

Repository Email cisadmin@lib.usc.edu