The relationship between body mass index, binge eating disorder and suicidality

Kristal Lyn Brown, Jessica Gokee LaRose, Briana Mezuk

While restrictive and compensatory eating disorders (e.g. anorexia and bulimia) are associated with elevated risk of suicide, less is known about binge eating disorder (BED). There is suggestive evidence of a U-shaped relationship between body mass index (BMI) and completed suicide, but fewer studies on suicidal ideation or attempts. This study examined the association between BED, BMI, and suicidality, and assessed whether these relationships varied by gender. Data come from the Collaborative Psychiatric Epidemiologic Surveys (N = 14,497). Binge episodes and BED were assessed using the Composite International Diagnostic Inventory (CIDI). BMI was calculated from self-reported height and weight. Suicidal ideation/attempts were assessed using the CIDI. Weighted logistic regression was used to assess the association between binging/BED, BMI and suicidality. Interaction terms were used to assess whether the relationship between BMI and suicidality was moderated by binging/BED, and whether the relationships between binging/BED and BMI differed by gender. One-third of adults with BED had a history of suicidality, compared to 19% of those without. Both binging (OR: 1.95, 95% CI: 1.50-2.53) and BED (OR: 2.01, 95% CI: 1.41-2.86) were associated with suicidality in fully-adjusted models. BMI was associated with suicidality in a curvilinear manner, and this relationship was exacerbated by binging/BED (ORBinge eating x BMI: 1.04, 95% CI: 1.01-1.09, p < 0.05). The relationship between BMI and suicidality did not differ by gender (ORgender x BMI: 1.00, p < 0.770). However, the relationship between binge eating and suicidality was stronger for women relative to men (ORgender X binge: 1.87, p < 0.012). Binge eating, even below the threshold for BED, is associated with suicidality. BMI is associated with suicidality in a curvilinear manner, and the BMI-suicidality relationship is potentiated by binge eating/BED. Findings support the thoughtful integration of psychiatric care into weight loss programs for adults with a history of binging behavior.