Weight gain, obesity, and metabolic indices following a first manic episode: Prospective 12-month data from the Systematic Treatment Optimization Program for Early Mania (STOP-EM)

Background: Numerous studies have demonstrated an association between bipolar disorder (BD) and obesity. However, these reports are limited by retrospective or cross-sectional designs, and the assessment of patients with lengthy illnesses. Prospective data, and data on weight gain early in the course of BD, are lacking. Methods: We prospectively measured weight gain and laboratory metabolic indices over 12 months in 47 patients with BD receiving maintenance treatment following their first manic episode, and in 24 age- and gender-matched healthy subjects. Results: Although approximately two-thirds of patients had experienced previous depressive or hypomanic episodes, there was no difference between patients and healthy subjects in mean body mass index or rates of overweight or obesity at recovery from the first mania. Mean weight gain over 12 months was 4.76 kg in patients and 1.50 kg in healthy subjects (p = 0.047). Combined rates of overweight and obesity at 6 months and 12 months exceeded 50% in patients, and were almost double those of healthy subjects. Logistic regression demonstrated that weight gain in the first 6 months was significantly associated with male gender and prescription of olanzapine or risperidone. Patients who were obese at 6 months and/or 12 months had significantly greater mean serum triglyceride levels and fasting glucose levels than non-obese patients. Limitations: This was a naturalistic study. Conclusions: Even in patients with previous depressions and hypomanias, clinically significant weight gain in BD begins following the first manic episode, suggesting that it is primarily related to treatment with mood stabilizers and second-generation antipsychotics. However, the very small number of patients in our sample who were medication-free precludes a meaningful analysis of the degree to which weight gain might be an inherent feature of post-manic BD.