Psychiatric comorbidity as a prospective predictor of long-term weight and psychosocial outcomes after bariatric surgery.

OBJECTIVES:Psychiatric comorbidity is common among the bariatric population although the prognostic significance of psychiatric comorbidity on outcomes is uncertain. This prospective study examined differences in weight and psychosocial functioning outcomes based on lifetime and current (post-surgical) psychiatric comorbidity. METHODS:Participants were 140 adults in a RCT for loss-of-control (LOC)-eating approximately six months post-bariatric surgery. Two structured interviews were administered: the Eating Disorder Examination-Bariatric Surgery Version (EDE-BSV) to assess LOC-eating and eating-disorder psychopathology, and the Mini International Neuropsychiatric Interview (MINI) to assess lifetime and current (post-surgical) psychiatric disorders. The EDE-BSV and Beck Depression Inventory (BDI-II) were repeated at post-treatment and 24-month follow-ups. RESULTS:Lifetime (75.7%) and current/post-surgical (25%) psychiatric diagnoses were common. Groups with and without psychiatric comorbidity did not differ significantly in weight loss outcomes at any timepoint but psychiatric comorbidity was associated significantly with greater LOC-eating, eating-disorder psychopathology, and depression. CONCLUSIONS:Among participants with LOC-eating post-bariatric surgery, lifetime and post-surgical psychiatric comorbidity was not associated with acute or longer-term weight outcomes but predicted poorer psychosocial functioning. Findings challenge prevailing views that psychiatric comorbidity is related to poorer longer-term weight outcomes following bariatric surgery but highlight its clinical significance as it is associated with broad psychosocial difficulties.