Chlorpromazine 1962.

Study characteristics
Methods	Randomisation: participants were ranked for morbidity, then matched, then randomised. Allocation: procedure not described. Blinding: double‐blind, identical capsules, each participant was provided medication in individual container. Staff guessed on which medication the participants were but could not guess adequately. Duration: 26 weeks. Design: parallel. Location: single‐centre. Setting: in hospital.
Participants	Diagnosis: chronic, long term hospitalised male psychotics (clinical diagnosis), 86 schizophrenia, 6 chronic brain syndrome, 2 personality disorders, 2 n.i.. N = 96. Gender: 96 men. Age: 43.6 years. History: duration stable‐ treated with chlorpromazine for at least 2 months, not ready for discharge, not assaultive, duration ill‐ n.i. but duration of current hospitalisation 12.3 years, number of previous hospitalisations NI‐, age at onset‐ n.i., severity of illness‐ n.i., baseline antipsychotic dose‐ 224 mg chlorpromazine per day.
Interventions	1. Drug: chlorpromazine ‐ Flexible dose. Allowed dose range: n.i.. Mean dose: n.i.. N = 48. 2. Placebo: duration of taper: 0 days. N = 48. Rescue medication: occasional use of sedatives, antipsychotics were not allowed.
Outcomes	Examined Relapse: condition worsened to such a point that ordinarily a complete change in treatment would be considered. Leaving early due to inefficacy. Unable to use/Not included Behaviour: Lyon’s Behaviour Scale (no SD / no prespecified outcome of interest).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were ranked for morbidity, then matched, then randomised.
Allocation concealment (selection bias)	Unclear risk	Procedure not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, identical capsules, each participant was provided medication in individual container. Staff guessed on which medication the participants were but could not guess adequately.
Blinding (performance bias and detection bias) Subjective outcomes	Low risk	Double‐blind, identical capsules, each participant was provided medication in individual container. Staff guessed on which medication the participants were but could not guess adequately.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double‐blind, identical capsules, each participant was provided medication in individual container. Staff guessed on which medication the participants were but could not guess adequately.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	It could be that there were participants leaving the study early but this was not clearly reported.
Selective reporting (reporting bias)	Low risk	No evidence for selective reporting.
Other bias	High risk	Blinding was broken once a participant relapsed.