- BACKGROUND: Patients with mood disorders have higher rates of obesity than the general population. With respect to this, little is known regarding how patient look like prior to treatment or the rates of change. OBJECTIVE: To identify changes in the rates of obesity in never-treated patients with mood disorder over 4 years of follow-up. METHODS: Sixty-six never-treated patients with mood disorders were evaluated via clinical interview, symptom assessment and body mass index (BMI). Patients were followed 4 years. Population attributable risk (PAR%) was calculated. RESULTS: Patients in underweight and normal weight groups fell by nearly 29%, with a corresponding increase in patients entering overweight and obese groups. Rates of PAR% increased to 16.0, a significant 5-point increase over baseline. LIMITATIONS: This study had a small sample size and the population was ethnically homogenous. BMI was used as a maker of weight and not waist circumference. CONCLUSIONS: Over 4 years there was a significant increase in BMI and the risk conferred by obesity. Shift from normal weight to overweight and obese is a significant risk for patients with a mood disorder and clinical programs should consider interventions that might ameliorate risk of this shift early in the course of the illness.