Obesity as a correlate of outcome in patients with bipolar I disorder

This study sought to evaluate the relationship of obesity to demographic and clinical characteristics and treatment outcome in a group of 175 patients with bipolar I disorder who were treated for an acute affective episode and followed through a period of maintenance treatment.

Data were from participants entering the Maintenance Therapies for Bipolar Disorder protocol between 1991 and 2000. Analyses focused on differences in baseline demographic and clinical characteristics and in treatment outcomes between obese and nonobese patients.

A total of 35.4% of the patients met criteria for obesity. Significant differences between the obese and nonobese patients were observed for years of education, numbers of previous depressive and manic episodes, baseline scores on the Hamilton Rating Scale for Depression, and durations of the acute episode. A Kaplan-Meier survival analysis indicated a significantly shorter time to recurrence during the maintenance phase among obese patients. The number of patients experiencing a depressive recurrence was significantly higher in the obese than in the nonobese group.

Obesity is correlated with a poorer outcome in patients with bipolar I disorder. Preventing and treating obesity in bipolar disorder patients could decrease the morbidity and mortality related to physical illness, enhance psychological well-being, and possibly improve the course of bipolar illness. Weight-control interventions specifically designed for patients with bipolar illness should be developed, tested, and integrated into the routine care provided for these patients.