Ten randomised controlled trials (RCTs) were included (n=522, range 10 to 207). Three reported adequate allocation concealment, nine were double blinded and eight used intention-to-treat analysis.
There was a significantly greater reduction in PANSS/BPRS scores in the intervention group (SMD -0.180, 95% CI -0.356 to -0.004, I2=33.5%; 10 RCTs).
Subgroup and meta-regression analyses showed that study duration had no statistically significant impact on effect size. There was no statistically significant difference between the groups in CGI scores (WMD -0.661, 95% CI -1.475 to 0.151, I2=78%; four RCTs) or in risk of withdrawal (RR 1.261, 95% CI 0.679 to 2.345, I2=0%; seven RCTs).
No evidence of obvious publication bias was detected.