Therapeutic Response Is Associated With Antipsychotic-Induced Weight Gain in Drug-Naive First-Episode Patients With Schizophrenia: An 8-Week Prospective Study

Background: Some previous studies have shown that weight gain is associated with greater improvement in psychopathology during antipsychotic treatment in patients with chronic schizophrenia. However, the results are mixed due to many confounding factors. The current study aimed to investigate whether weight gain was associated with antipsychotic response in patients with antipsychotic-naive and first-episode (ANFE) DSM-IV-diagnosed schizophrenia. Methods: 526 ANFE patients and 313 healthy controls were enrolled in this study, which was conducted from January 2012 to December 2018. Treatment outcome was measured by the Positive and Negative Syndrome Scale (PANSS) at baseline and follow-up. Weight was measured at baseline and at the end of 8 weeks. Results: After treatment, PANSS scores were significantly reduced as follows: positive symptoms (-10.40; 95% CI, -9.31 to -10.60), negative symptoms (-5.01; 95% CI, -4.43 to -5.54), general psychopathology (-13.01; 95% CI, -12.01 to -14.01), and PANSS total score (-28.53; 95% CI, -26.73 to -30.33). In addition, the average weight of ANFE patients increased by 2.89 kg (95% CI, 2.55 to 3.22), although it was still lower than the average weight of healthy controls. The proportion of patients with weight gain >= 7% after treatment was 38.2%. Weight gain was positively associated with decrease of PANSS positive symptoms, general psychopathology, and total score (all P < .05). Multiple linear regression analysis showed that baseline weight, decrease of PANSS total score, and sex were significantly associated with weight gain after treatment. Conclusions: Our findings suggest that there is a significant association between weight gain and improvement of clinical symptoms after 8 weeks of antipsychotic treatment in patients with ANFE schizophrenia.