Effectiveness of a Cognitive Behavioral Weight Management Intervention in Obese Patients With Psychotic Disorders Compared to Patients With Nonpsychotic Disorders or No Psychiatric Disorders: Results From a 12-month, Real-World Study

Studies of behavioral weight loss intervention in patients with psychotic disorders are sparse, and its efficacy compared to other obese patients is unknown. Therefore, we compared the effect of a cognitive-behavioral weight loss intervention in obese subjects with psychotic disorders, other psychiatric diagnoses, and without psychiatric disorders. A 12-month naturalistic study of weekly group or individual cognitive-behavioral weight management in 222 consecutively enrolled obese patients (body mass index [BMI], 43.7 ± 9.6 kg/m2) with psychotic spectrum disorders (PSDs, n = 47), other psychiatric disorders (OPDs, n = 49), and no psychiatric disorder (NPD, n = 126). Patients with PSD had greater treatment persistence (48.9%) and longer treatment duration (8.7 ± 4.4 months) than those with OPD (22.4% and 5.4 ± 4.3 months) and NPD (22.2% and 4.9 ± 4.7 months) (P < 0.01 for all; number needed to treat, 3). In last-observation-carried-forward analyses, patients with PSD had greater percent baseline weight loss at 12 months (5.1% ± 9.3%) than patients with OPD and with NPD (2.7% ± 5.5% and 2.4% ± 6.3%); greater percent BMI loss at 9 and 12 months than both groups (P < 0.05 for all) and greater BMI loss at 9 months (2.1 ± 3.5 kg/m2) and 12 months (2.3 ± 4.1 kg/m2) than NPD patients (1.1 ± 2.3 and 1.2 ± 2.4 kg/m2). Furthermore, weight loss of 5% or more occurred in 42.6% of patients with PSD versus 18.4% and 23.0% in OPD and NPD patients (P < 0.01 for all; numbers needed to treat, 5 and 6). The strongest weight loss predictor was treatment duration (β = 0.51-0.54; P < 0.001). Attrition was predicted by NPD (P = 0.001) and OPD group status (P = 0.036), lower proportion of group sessions (P = 0.002), higher depression (P = 0.028), and lower baseline BMI (P = 0.030). Patients with PSD had greater weight loss than other obese patients. Nonadherence and depression should be targeted to enhance weight loss success.