Kurihara 1983.

Methods	Allocation: randomised. Blindness: double. Duration: 8 weeks. Setting: multi‐centre, Japan.
Participants	Diagnosis: schizophrenia. N = 286. Age: no details. Sex: 124 F, 160 M. History: inpatient. Included: not clear. Excluded: severe excitement; severe stupor; severely delusional hallucinatory; severely deteriorated; hepatic; cardiac or haematological disturbance; pregnancy or suspected; children; elderly people. Consent: not clear.
Interventions	1. Perphenazine: initially 9 mg (3 tablets) daily for one week, 18 mg during the second week, then individual dosage according to symptoms and adverse events, n = 95. 2. Clocapramine: initially 75 mg (3 tablets) daily for one week, 150 mg during the second week, then individual dosage according to symptoms and adverse events, n = 97. 3. Haloperidol: initially 3 mg (3 tablets) daily for one week, 6 mg during the second week, then individual dosage according to symptoms and adverse events, n = 94.
Outcomes	Leaving the study early. Global state: no better or worse. Adverse events. Unable to use ‐ Mental state: Psychiatric Rating Scale (unpublished scale). Behaviour: Evaluation of Behaviour (no SD).
Notes	Additional medication: sedatives such as nitrazepam, amobarbital, bromvalerylurea and antiparkinsonians such aspromethazine, biperiden, trihexyphenidyl were given if needed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised: no further details.
Allocation concealment (selection bias)	Unclear risk	Not clear.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Double‐blind: identical appearance of capsules.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not clear.
Selective reporting (reporting bias)	Unclear risk	Not clear.
Other bias	Unclear risk	Funding: not clear. Raters: not stated to be independent of treatment.