Weight gain correlates with greater symptom improvements for antipsychotic treatment

Patients with antipsychotic-naive and first-episode schizophrenia who received antipsychotic treatment experienced weight gain and improvement of clinical symptoms following 8 weeks of treatment.

“There was a significant correlation between antipsychotic-induced weight gain and psychopathological reduction,” Ying Qi Chen, MD, PhD, of Beijing Chao-Yan Hospital at the Capital Medical University, and colleagues wrote. “These results support the notion that there exists a significant relationship between antipsychotic response and weight gain, and thereby the clinical benefits of antipsychotic treatment and weight gain must be evaluated in the early stages of the disease.”

Chen and colleagues examined the association between weight gain and psychopathology improvements during treatment in patients with chronic schizophrenia. In this longitudinal, observational clinical study conducted in China between January 2012 and December 2018, 441 patients with schizophrenia and 313 control patients received monotherapy with an antipsychotic for 8 weeks; 30% of patients were also taking anticholinergic medications. Dosage was flexible but the type of antipsychotic remained consistent. All patients were hospitalized and monitored to ensure they were taking the medication. Chen and colleagues collected data on height, waist and hip measurements, bodyweight and BMI at baseline and at the end of 8 weeks, averaging the values. They considered weight gain an increase of 7% or more of the patient’s baseline weight. Psychiatrists assessed improvements in psychotic symptoms using the Positive and Negative Syndrome Scale (PANSS).

The number of male and female patients included in the study was relatively even, and participants had a mean age of 27.3 years. Prior to treatment, patients had an average weight of 58.6 kg (95% CI, 54.8 to 60.9) and BMI of 21.4 kg/m2 (95% CI, 21.2 to 22.2). Compared with controls, patients with schizophrenia had lower weight and BMI to start. After 8 weeks of treatment, patients exhibited significantly lower PANSS scores than at baseline, with an average PANSS positive symptoms score of 10.4 (95% CI, 9.31-10.6), negative symptoms score of 5.01 (95% CI, 4.43-5.54), general psychopathology of 13.01 (95% CI, 12.01-14.01) and a total score of 28.53 (95% CI, 26.73-30.33).

After treatment, patients experienced a significant amount of weight gain of 2.89 kg on average (95 CI%, 2.55 to 3.22). The researchers observed a significant association between weight gain, age at onset, the course of disease and education. Also, weight gain was significantly and positively associated with a decrease in PANSS scores, with lower PANSS scores considered predictive of weight gain. However, despite 8 weeks of treatment, patients with schizophrenia had lower body weights than patients in the control group. On average, patients weighed 61.3 kg after treatment. Among those with schizophrenia, patients who gained weight experienced greater symptom improvements than those who did not.

“The weight of the [weight gained] group at baseline was significantly lower than that of the [non-weight gained] group, suggesting that patients with lower body weight were more likely to gain weight after 8 weeks of antipsychotic monotherapy,” Chen and colleagues wrote. “In addition, it is noteworthy that the associations between weight gain and symptom improvement were weak.”