Download Identifying the Core Symptoms of Bulimia Nervosa and Associated

IDENTIFYING THE CORE SYMPTOMS OF BULIMIA NERVOSA
AND ASSOCIATED ANXIETY AND DEPRESSION
CHERI LEVINSON, STEPHANIE ZERWAS, BENJAMIN CALEBS, KELSIE FORBUSH, HUNNA WATSON, HANS KORDY, SARA HOFMEIER, MICHELE
LEVINE, BENJAMIN ZIMMER, MARKUS MOESSNER, CHRISTINE PEAT, CRISTIN RUNFOLA, MARSHA MARCUS, CYNTHIA BULIK
WHAT IS AT THE CORE OF BULIMIA NERVOSA?
 Bulimia nervosa (BN) is characterized by symptoms of:
 binge eating and compensatory behavior
 overevaluation of weight and shape
 BN symptoms often co-occur with symptoms of anxiety and depression
 Which specific BN symptoms maintain BN psychopathology?
 How are these symptoms associated with symptoms of depression and anxiety?
Fairburn, Cooper, & Shafran, 2003; Palister & Waller, 2008
MODELS OF PSYCHOPATHOLOGY
 Latent variable theory often used to describe why mental disorders
develop & persist
 Symptoms arise from a common cause
BN
Fear of
weight gain
Binge eating
Purging
Avoidance
of food
 BN is the cause that leads to each of these common symptoms.
Bollen, 2002; Borsboom et al., 2016; Clark & Watson, 1991; Eaton, 2015; Haslam, Holland, & Kuppens, 2012
NETWORK THEORY
 Network theory proposes that symptoms of disorders cause each
other
 Symptoms are part of a dynamic network which can produce,
sustain, and underlie mental disorders
Fear of
Weight
Gain
Avoidance
of food
Binge
eating
Purging
 These interact with each other to strengthen (or weaken) the disorder
Borsboom & Cramer, 2010; Borsboom & Cramer, 2013; Kendler, Zachar, & Craver, 2011
WHAT CAN NETWORK ANALYSIS TEACH US?
 Determine the symptoms that are central to the BN
psychopathology network
 Examine how symptoms of comorbid disorders interact with
symptoms of BN
CLINICAL UTILITY
 Reducing core symptoms in treatment should
theoretically also decrease related symptoms
 Focus interventions to target:
 core symptoms−symptoms play a crucial role in the network
 comorbid symptoms that link between multiple disorders
Hayes, Yasinski, Barnes, & Bockting, 2015
CURRENT STUDY
Examined:
1. A network of BN symptoms:
Which symptoms are most central (i.e. core symptoms)?
2. The networks of BN, depression, and anxiety symptoms:
Which depression and anxiety symptoms are most strongly related to BN symptoms?
PARTICIPANTS
 196 patients recruited for a clinical trial
 All patients had DSM-IV diagnosis of BN
 Primarily female (n = 187; 95.4%)
 European American (n = 165; 84.2%)
 Majority had comorbid depression and/or anxiety (n = 136; 69.4%)
MEASURES
 Eating Disorder Examination
 Binge eating, restriction, fears of fatness
 Short Evaluation of Eating Disorders
 Vomiting, purging, excessive exercise
 Beck Anxiety Inventory
 Scared, dizziness
 Beck Depression Inventory-II
 Sad, fatigue, self-dislike
Bauer et al., 2005; Beck, Steer, & Brown, 1996; Fairburn & Cooper, 1993; Steer & Beck, 1997
NETWORK ANALYSES
 Partial Correlation Networks (Glasso Estimator)
 Explains how symptoms relate while also considering the impact of all other
symptoms
 Bridge Symptoms
 Symptoms that link adjacent symptoms together and are theorized to be
pathways that could causally connect symptoms or behaviors
 Centrality Measures
 Betweenness – number of times symptom is passed through
 Closeness – closeness to other symptoms in the network
 Strength – having many connections to other symptoms
 BN Network
BULIMIA NERVOSA PSYCHOPATHOLOGY NETWORK
CLOSENESS
BETWEENESS
Betweenness
STRENGTH
Closeness
Strength
**weight preoccupation
wtpreoc
wtimport
**weight dissatisfaction
**
wtdis
weigh
vomit
socialeat
shapeimport
shapedis
secreteat
restrict
Higher peaks on
right side indicate
higher centrality
preoc
overeat
losscontrol
** weight
**lose
losewt
guilt
**highest centrality
items
foodavoid
flatstom
feelfat
**fear weight gain
**
fearwtgain
fast
expodisc
excesexer
emptystom
dietrule
bodydisc
binge
avoideat
−1
0
1
2
−2
−1
0
1
−2
−1
0
1
exces
exer
fast
empty
stom
hot
BN AND ANXIETY NETWORK
avoid
eat
flat
stom
food
avoid
sweat
over
eat
restrict
weigh
diet
rule
dizzy
faint
un
steady
lose
wt
feel
fat
expo
disc
body
disc
shape
import
Bulimia Nervosa &
Anxiety Network
heart
pound
terrified
shaky
diffb
choking
nervous
cant
relax
scared
tingle
social
eat
wtdis
wt
import
lose
control
guilt
shape
dis
face
flush
wobble
hand
tremble
fear
wtgain
indiges
tion
fear
worst
wt
preoc
secret
eat
loss
control
preoc
vomit
binge
fear
die
BETWEENESS
**weight preoccupation
**
CLOSENESS
Betweenness
STRENGTH
Closeness
Strength
wtpreoc
wtimport
wtdis
wobble
weigh
vomit
**unsteady
**terrified
unsteady
tingle
terrified
sweat
socialeat
**shapedis
**shape dissatisfaction
shaky
shapeimport
Higher peaks
on right side
indicate higher
centrality
secreteat
scared
restrict
preoc
overeat
nervous
losscontrol
losewt
** losecontrol
**lose
control
indigestion
hot
**highest
centrality items
heartpound
handtremble
guilt
foodavoid
flatstom
feelfat
**fear weight
gain
**fearwtgain
fearworst
feardie
fast
faint
faceflush
expodisc
excesexer
emptystom
dizzy
diffb
**choking
**
dietrule
choking
cantrelax
bodydisc
binge
** eating
**avoid
avoideat
−1
0
1
2
−4
−3
−2
−1
0
1
−2
−1
0
1
exces
exer
over
eat
restrict
food
avoid
fast
weigh
diet
rule
flat
stom
fear
wtgain
avoid
eat
empty
stom
BN AND DEPRESSION NETWORK
agita
tion
self
dislike
inde
cisive
irritable
loss
pleasure
sleep
fatigue
Bulimia Nervosa &
critical
punish
low
energy
Depression Network
loss
interest
worth
less
sad
shape
import
expo
disc
secret
eat
body
disc
wt
preoc
past
fail
preoc
appetite
pessim
con
centrate
wt
import
feel
fat
shape
dis
guilty
guilt
lose
wt
wtdis
crying
social
eat
suicide
sex
vomit
binge
loss
control
BETWEENESS
**weight preoccupation
CLOSENESS
Betweenness
**
STRENGTH
Closeness
Strength
wtpreoc
wtimport
wtdis
worthless
weigh
vomit
suicide
socialeat
sleep
shapeimport
shapedis
sex
selfdislike
secreteat
**
**sad
sad
restrict
punish
preoc
pessim
pastfail
Higher peaks on
right side
indicate higher
centrality
overeat
lowenergy
losspleasure
lossinterest
losscontrol
losewt
**irritable
**
irritable
indecisive
guilty
guilt
foodavoid
**highest
centrality items
flatstom
feelfat
**fear weight
gain
fearwtgain
**
fatigue
fast
expodisc
excesexer
emptystom
dietrule
crying
critical
**concentrate
concentrate
**
bodydisc
binge
avoideat
appetite
agitation
−1
0
1
2
−2
−1
0
1
2
−2
−1
0
1
2
CONCLUSIONS
 Core BN symptoms
 fear of weight gain & overevaluation of weight and shape
 Bridge symptoms - connect anxiety or depression symptoms to BN
 Physical sensations: unsteady, fears of losing control, choking, difficulty
concentrating may be bridge symptoms
FEAR OF WEIGHT GAIN
 Fear of weight gain is central to BN network
 Binge eating and purging on the periphery
 Treatments that focus on fear of weight gain may have maximal impact
 Weekly weighing
 Exposure
PHYSICAL SENSATIONS
 Physical sensations bridge BN & anxiety/depression
 Exaggerated insula response in eating disorders?
 Sensitivity to physical sensations
 Interoceptive Exposures
Kim et al., 2012; Fassino, Pierò, Gramaglia, & Abbate-Daga, 2004; Klabunde et al., 2013; Oberndorfer et al., 2013
LIMITATIONS
 Data is cross-sectional – no causality
 Limited measurement of each symptom
 Applying network analysis to psychopathology is new
 No fit indices
 No measures of reliability
 Limited by measures and symptoms chosen for the network
FUTURE DIRECTIONS
 Does change in a core symptom produce changes in
other network symptoms?
 Do symptom networks become less strong after
treatment and with symptom remission?
ACKNOWLEDGMENTS & DISCLOSURES
 Dr. Bulik is a grant recipient and consultant for Shire Pharmaceuticals and has consulted for Ironshore. Dr. Marcus is on
the Scientific Advisory Board of Weight Watchers International, Inc. Dr. Peat is recipient of a contract from RTI and Shire
Pharmaceuticals and has consulted for Sunovion Pharmaceuticals, L.E.K consulting, and Nexus Global Solutions. Dr.
Watson is supported by a research grant from Shire awarded to UNC-Chapel Hill. Dr. Zerwas has consulted for L.E.K
consulting.
 This research was supported by a National Institute of Mental Health (NIMH) grant (R01MH080065), a Clinical
Translational Science Award (UL1TR000083), and the Alexander von Humboldt-Stiftung. Dr. Zerwas is supported by a
NIMH career development grant (K01MH100435). Drs. Peat and Runfola were supported by a NIMH post-doctoral
training grant (T32MH076694). Dr. Runfola was supported by the Global Foundation for Eating Disorders (PIs: Bulik and
Baucom; www.gfed.org). Benjamin Zimmer was supported by a Fellowship for Postdoctoral Researchers from the
German Academic Exchange Service (DAAD). Dr. Bulik acknowledges support from the Swedish Research Council (VR
Dnr: 538-2013-8864).
 We wish to honor the incredible contribution and legacy of our colleague Dr. Robert Hamer, who passed away in
December 2015.