Freeman 1962.

Methods	Allocation: randomly assigned, pairs matched on morbidity. Blinding: double, identical capsules, "neither experimenters nor staff knew which patients were receiving the placebo". Duration: 6 months.
Participants	Diagnosis: psychosis (86 schizophrenia, 6 chronic brain syndrome, 2 personality disorders). N=94. Age: mean 44 yrs. Sex: all males. History: "chronic" in hospital >12 yrs, only on chlorpromazine in last 2 months. Excluded: physically assaultive, considered for discharge. Setting: hospital.
Interventions	1. Chlorpromazine cessation: placebo. N=46. 2. Chlorpromazine continuation: dose 220 mg/day. N=48. Sedatives were permitted for occasional use when required.
Outcomes	Relapse. Unable to use ‐ Behaviour change: LBRS (no usable data).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear