Correlates of Overweight and Obesity in 644 Patients With Bipolar Disorder

Objective: Overweight and obesity are common clinical problems encountered in the treatment of bipolar disorder. We therefore assessed the prevalence and clinical correlates of overweight, obesity, and extreme obesity in 644 bipolar patients.

Method: 644 outpatients with DSM-IV bipolar disorder in the Stanley Foundation Bipolar Treatment Outcomes Network were evaluated with structured diagnostic interviews and clinician- and self-administered questionnaires to determine bipolar disorder diagnoses, demographic and historical illness characteristics, comorbid Axis I diagnoses, medical histories, health habits, and body mass indices (BMIs).

Results: Fifty-eight percent of the patients with bipolar disorder were overweight, 21% were obese, and 5% were extremely obese. American patients had significantly higher mean (p<.0001) BMIs and significantly higher rates of obesity (p<.001) and extreme obesity (p<.001) than European patients. Significant associations (p.001) were found between overweight, obesity, and extreme obesity and gender, age, income level, comorbid binge-eating disorder, hypertension, arthritis, diabetes mellitus, exercise habits, and coffee consumption. Current BMI and weight were each correlated with the number of weight gain-associated psychotropics to which patients had been exposed. Multinomial logistic regression (adjusted for site and eating disorder diagnosis and corrected for multiple comparisons) showed that (1) overweight was significantly associated with male gender and hypertension (p<.001), (2) obesity was significantly associated with hypertension (p<.001), and (3) extreme obesity was significantly associated with hypertension and arthritis (p<.001).

Conclusion: Overweight, obesity, and extreme obesity were common in this group of bipolar patients, although it was unclear that their prevalence rates were truly elevated, because overweight and obesity are increasingly common public health problems among the general population. Correlates of overweight and obesity in bipolar disorder include patient and treatment variables such as gender, geographical location, comorbid binge-eating disorder, age, income level, degree of exposure to weight gain-associated psychotropics, medical disorders associated with obesity, and health habits.