Potkin 2007.

Methods	Allocation: randomised. Blindness: double. Duration: 6 weeks. Setting: 21 sites in USA. Design: parallel.
Participants	Diagnosis: schizophrenia. N = 180. Age: 18 to 65 years. Sex: not reported. History: participants with acute exacerbation were included in the trial. Inclusion criteria: baseline PANSS score > 60. Exclusion criteria: recent history of suicide attempt or serious suicide thoughts, neurological disorders other than TD or EPS, psychoactive substance dependence or history of drug or alcohol abuse within 1 month.
Interventions	1. Risperidone: dose 6 mg/day, N = 59. 2. Placebo: N = 62. 3. Asenapine: dose 10 mg/day, N = 59.
Outcomes	Leaving the study early. Adverse effects. Unable to use: Global state: CGI (> 50% loss to follow‐up, thus data was not reported). Mental state: PANSS (> 50% loss to follow‐up, thus data was not reported). Function: battery of neurocognitive test (no SD reported), WCST (no data reported).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised, no further information.
Allocation concealment (selection bias)	Unclear risk	No information available.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double dummy placebo design was employed to maintain blinding. Quote: "this double‐blind, double‐dummy, 3‐arm, fixed‐dose..." (p1493).
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT for efficacy data and LOCF for safety data.
Selective reporting (reporting bias)	Low risk	All outcomes measured were reported.
Other bias	High risk	Funded by Organon USA Inc and Pfizer Inc.