Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
PTSD symptoms
Systematic review	37 people Data from 1 RCT	Reduction in severity of clinician-rated PTSD symptoms 5 weeks with adjunctive risperidone with placebo Absolute results not reported	SMD +0.10 95% CI –0.55 to +0.74 The results from this RCT should be interpreted with caution because of the variability in the other medications being taken		Not significant
RCT	65 men with PTSD after military service	Mean change in Clinician Administered PTSD Scale score –14.3 with adjunctive risperidone 3 mg daily for 4 months –4.6 with placebo	P <0.05	Effect size not calculated	risperidone
RCT	21 women with PTSD	Mean change in Clinician Administered PTSD Scale score –29.6 with risperidone 0.5–8 mg (mean 1.41 mg) daily for 8 weeks –18.6 with placebo	P = 0.015	Effect size not calculated	risperidone