A Cochrane review included 3 studies with a total of 310 subjects. One trial found no significant difference between quetiapine and haloperidol for the outcome of 'less than 50% reduction in PANSS score' (n=180, RR 0.91 CI 0.8 to 1.0). Those allocated sulpiride had significantly lower depression scores compared with people given chlorpromazine (1 RCT, n=36, WMD CPRS -0.70 CI -1.2 to -0.2). Clozapine constantly scored better on Hamilton scores than other antipsychotic drugs plus an antidepressant or placebo, (1 RCT, n=29, WMD vs antipsychotic + mianserin -5.53 CI -8.23 to -2.8; 1 RCT, n=32, WMD vs antipsychotic + meclobemide -4.35 CI -6.7 to -2.03; 1 RCT, n=33, WMD vs antipsychotic + placebo - 6.35 CI -8.6 to -4.1).
Comment: The quality of evidence is downgraded by imprecise results (limited study size for each comparison, few patients and wide confidence intervals) and by inconsistency (heterogeneity in interventions and outcomes).