Various drugs 1960.

Study characteristics
Methods	Randomisation: random, no further details. Allocation: procedure not described. Blinding: double‐blind, unidentifiable capsules. Duration: 6 months. Design: parallel. Location: single‐centre. Setting: outpatient.
Participants	Diagnosis: chronic psychotic patients (mainly schizophrenia, clinical diagnosis). N = 144. Gender: n.i.. Age: n.i.. History: duration stable‐ "observed on the same drugs for 4.5 months”, duration ill‐ n.i., number of previous hospitalisations‐ n.i., age at onset‐ n.i., severity of illness‐ n.i., baseline antipsychotic dose‐ n.i..
Interventions	1. Drug: continuation of antipsychotic taken before the study ‐ Fixed/flexible dose: unclear. Allowed dose range: unclear. Mean dose: n.i.. N = 46. 2. Placebo: duration of taper: "4 weeks to five months, usually 2 months”. N = 98. Rescue medication: n.i..
Outcomes	Examined Relapse: clinical diagnosis. Unable to use/Not included Social adjustment: (not reported for the randomised participants). Rehospitalisation (unclear numbers).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random, no further details.
Allocation concealment (selection bias)	Unclear risk	Procedure not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double‐blind, unidentifiable capsules.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double‐blind, unidentifiable capsules.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double‐blind, unidentifiable capsules.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Whether participants left the study early is unclear.
Selective reporting (reporting bias)	Low risk	No evidence for selective reporting.
Other bias	High risk	In case of relapse the blind was broken.