OBJECTIVE: The present study aimed to examine the changes in pro-inflammatory cytokines and body weight during 6-month risperidone treatment in drug naive, first-episode schizophrenia.

METHODS: Sixty-two drug naive, first-episode schizophrenia (SZ group) and 60 healthy individuals (control group) were enrolled in the study. Serum interleukin-1beta (IL-1beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) levels, and body weight were measured at baseline for both groups, and repeated for the SZ group at five different time points during 6-month risperidone treatment.

RESULTS: At baseline, serum IL-1beta, IL-6, and TNF-alpha levels in the SZ group (53.28 +/- 12.62, 33.98 +/- 14.13, 50.08 +/- 12.86 pg/mL, respectively) were significantly higher than those in the control group (23.49 +/- 15.27, 15.53 +/- 7.16, 32.12 +/- 15.23 pg/mL, respectively) (p's < 0.001). Within the SZ group, serum IL-1beta levels decreased significantly at 2 weeks (48.02 +/- 16.00 pg/mL, p < 0.01) and 1 month (44.70 +/- 16.63 pg/mL, p < 0.001), but then gradually increased at 2 months (48.49 +/- 18.87 pg/mL), 3 months (50.59 +/- 18.48 pg/mL) and 6 months (53.64 +/- 16.22 pg/mL) to the levels comparable to baseline; serum IL-6 levels changed significantly over the course of treatment (p = 0.001), but reached the levels comparable to baseline at 6 months (37.13 +/- 13.23 pg/mL); serum levels of TNF-alpha increased significantly at 3 months (55.02 +/- 16.69 pg/mL, p < 0.01) and 6 months (58.69 +/- 13.57 pg/mL, p < 0.001); steady and significant weight gain was observed at each follow-up time point (p's < 0.001), from 56.71 +/- 9.25 kg at baseline to 62.72 +/- 9.53 kg at 6 months.

CONCLUSIONS: Risperidone treatment is associated with changes in serum pro-inflammatory cytokines levels and weight. There is an initial anti-inflammatory effect that reduces with treatment, potentially due to its weight gain side effect.