Body mass index, depression, and suicidality: The role of self-esteem in bariatric surgery candidates

- 3101 bariatric surgery candidates.
- Self-esteem mediated the relationship between body mass index (BMI) and depression.
- The relationship between BMI and suicidality was mediated by self-esteem.
- The mediated pathways were stronger for males, than for females.
- Findings may be used to optimize depression and interventions.

BackgroundPrevious research suggests a relationship between weight and depression/suicidality, although few studies have examined the mechanisms underlying this association. This study examined the mediating role of self-esteem in the relationship between BMI and depression/suicidality, as well as the moderating role of gender in the mediated pathways.MethodsAs part of a screening process in consideration for bariatric surgery, 3,101 adults (81.4% female, 18.6% male) were assessed one time. Five univariate mediation and five univariate moderated-mediation models were hypothesized and analyzed. For the mediation models, we entered five outcome variables separately: 1) severity of depressed mood, 2) diagnosis of Major Depressive Disorder, 3) lifetime history of suicide attempts, 4) suicidal ideation at the time of evaluation, and 5) severity of suicidality, BMI as the independent variable, and self-esteem as the mediator. For the moderated-mediated models, gender was examined as a moderator to examine whether self-esteem was a stronger mediator for one gender, compared to the other.ResultsFindings supported the mediating role of self-esteem across all five outcomes. Further, the mediated effect was moderated by gender, such that the mediation effect was stronger for males, compared to females.LimitationsThe majority of the sample consisted of White females, limiting broad applicability of findings. All variables were assessed simultaneously, at baseline, limiting the ability to make causal attributions.ConclusionsStudy findings suggest that self-esteem may help explain the relationship between BMI and depression/suicidality, particularly for men. Thus, interventions targeting self-esteem may be useful for improving psychological outcomes among those presenting for bariatric surgery.