The core symptoms of bulimia nervosa, anxiety, and depression: A network analysis

Abstract

Bulimia nervosa (BN) is characterized by symptoms of binge eating and compensatory behavior, and overevaluation of weight and shape, which often co-occur with symptoms of anxiety and depression. However, there is little research identifying which specific BN symptoms maintain BN psychopathology and how they are associated with symptoms of depression and anxiety. Network analyses represent an emerging method in psychopathology research to examine how symptoms interact and may become self-reinforcing. In the current study of adults with a Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition (DSM-IV) diagnosis of BN (N = 196), we used network analysis to identify the central symptoms of BN, as well as symptoms that may bridge the association between BN symptoms and anxiety and depression symptoms. Results showed that fear of weight gain was central to BN psychopathology, whereas binge eating, purging, and restriction were less central in the symptom network. Symptoms related to sensitivity to physical sensations (e.g., changes in appetite, feeling dizzy, and wobbly) were identified as bridge symptoms between BN, and anxiety and depressive symptoms. We discuss our findings with respect to cognitive-behavioral treatment approaches for BN. These findings suggest that treatments for BN should focus on fear of weight gain, perhaps through exposure therapies. Further, interventions focusing on exposure to physical sensations may also address BN psychopathology, as well as co-occurring anxiety and depressive symptoms. (PsycINFO Database Record

Trial registration: ClinicalTrials.gov NCT00877786.

Figure 1

BN Network. Note. BN symptom label descriptions: avoideat = avoidance of eating; binge = bingeing; bodydisc = body discomfort; dietrule = dieting rules; emptystom = desire for an empty stomach; excesexer = excessive exercising; expodisc = discomfort with exposure; fast = fasting; fearwtgain = fear of weight gain; feelfat = feelings of fatness; flatstom = desire for flat stomach; foodavoid = food avoidance; guilt = guilt over eating; losewt = desire to lose weight; losscontrol = loss of control over eating; overeat = overeating; preoc = preoccupation with weight/shape; restrict = restriction; secreteat = eating in secret; shapedis = overevaluation of shape; shapeimport = shape importance; socialeat = avoiding eating in social settings; vomit = vomiting; weigh = reaction to prescribed weighing; wtdis = overevaluation of weight; wtimport = weight importance; wtpreoc = preoccupation with weight. Tie strength is indicated by line thickness between nodes with thicker lines representing stronger ties.

Figure 2

Centrality Indices for BN Network. Note. Higher numbers indicate that the item is more central to the network; highest four values are indicated within each index by a red dot; symptoms with at least two of the highest centralities are bolded. Values shown on the x-axis are standardized z-scores.

Figure 3

BN and Anxiety Network. Note. BN symptom label descriptions: avoideat = avoidance of eating; binge = bingeing; bodydisc = body discomfort; dietrule = dieting rules; emptystom = desire for an empty stomach; excesexer = excessive exercising; expodisc = discomfort with exposure; fast = fasting; fearwtgain = fear of weight gain; feelfat = feelings of fatness; flatstom = desire for flat stomach; foodavoid = food avoidance; guilt = guilt over eating; losewt = desire to lose weight; losscontrol = loss of control over eating; overeat = overeating; preoc = preoccupation with weight/shape; restrict = restriction; secreteat = eating in secret; shapedis = overevaluation of shape; shapeimport = shape importance; socialeat = avoiding eating in social settings; vomit = vomiting; weigh = reaction to prescribed weighing; wtdis = overevaluation of weight; wtimport = weight importance; wtpreoc = preoccupation with weight. Anxiety symptom label descriptions: cantrelax = unable to relax; choking = feeling of choking; diffb = difficulty breathing, dizzy = dizzy or lightheaded; faceflush = face flushed; faint = feeling faint/lightheaded; feardie = fear of dying; fearworst = fear of worst happening; handtremble = hands trembling; heartpound = heart pounding/racing; hot = feeling hot; indigestion = indigestion; losecontrol = fear of losing control; nervous = feeling nervous; scared = feeling scared; shaky = feeling shaky; sweat = hot/cold sweats; terrified = terrified/afraid; tingle = numbness or tingling; unsteady = unsteady; wobble = wobbliness in legs. Tie strength is indicated by line thickness between nodes with thicker lines representing stronger ties.

Figure 4

Centrality Indices for BN and Anxiety Network. Note. BN symptoms are denoted in red and anxiety symptoms in green; higher numbers indicate that the item is more central to the network; highest four values for each disorder are indicated within each index by a red dot for BN and a green dot for anxiety; symptoms with at least two of the highest centralities are bolded. Values shown on the x-axis are standardized z-scores.

Figure 5

BN and Depression Network. Note. BN symptom label descriptions: avoideat = avoidance of eating; binge = bingeing; bodydisc = body discomfort; dietrule = dieting rules; emptystom = desire for an empty stomach; excesexer = excessive exercising; expodisc = discomfort with exposure; fast = fasting; fearwtgain = fear of weight gain; feelfat = feelings of fatness; flatstom = desire for flat stomach; foodavoid = food avoidance; guilt = guilt over eating; losewt = desire to lose weight; losscontrol = loss of control over eating; overeat = overeating; preoc = preoccupation with weight/shape; restrict = restriction; secreteat = eating in secret; shapedis = overevaluation of shape; shapeimport = shape importance; socialeat = avoiding eating in social settings; vomit = vomiting; weigh = reaction to prescribed weighing; wtdis = overevaluation of weight; wtimport = weight importance; wtpreoc = preoccupation with weight. Depression symptom label descriptions: agitation = feeling agitated and restless; appetite = changes in appetite; concentrate = concentration difficulties; critical = self-criticalness; crying = crying too much or too little; fatigue = tiredness or fatigue; guilty = feeling guilty; indecisive = difficulty making decisions; irritable = irritability; lossinterest = loss of interest; losspleasure = loss of pleasure; lowenergy = loss of energy; pastfail = past feels like a failure; pessim = pessimism; punish = punishment feelings; sad = sadness; selfdislike = disliking self; sex = loss of interest in sex; sleep = changes in sleeping pattern; suicide = suicidal ideation; worthless = feelings of worthlessness. Tie strength is indicated by line thickness between nodes with thicker lines representing stronger ties.

Figure 6

Centrality Indices for BN and Depression Network. Note. BN symptoms are denoted in red and depression symptoms in blue; higher numbers indicate that the item is more central to the network; highest four values for each disorder are indicated within each index by a red dot for BN and a blue dot for depression; symptoms with at least two of the highest centralities are bolded. Values shown on the x-axis are standardized z-scores.