Caffey 1964.

Methods	Allocation: randomly assigned. Blinding: double, identical capsules. Duration: 16 weeks (preceded by 3 months stabilisation on either chlorpromazine or thioridazine).
Participants	Diagnosis: schizophrenia. N=438 (269 to relevant interventions). Age: < 56, mean 40 yrs. Sex: all males. History: in hospital >2yrs, mean 10 yrs. Excluded: CNS disease, any seizures, prefrontal lobotomy.
Interventions	1. Chlorpromazine cessation: placebo. N=171. 2. Chlorpromazine or thioridazine intermittent treatment: dose 400 mg, 350 mg respectively 3 days a week. N=89. 3. Chlorpromazine or thioridazine continuation: dose 400 mg, 350 mg/day respectively. N=88.
Outcomes	Relapse. Unable to use ‐ Global state: IMPS (no SD), Ward Evaluation Scale (no data). Behaviour change: PRP (no SD). Biochemistry: urine test (no SD).
Notes	* Data not detailed for each drug. We considered CPZ and Thioridazine patients as one group.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear