Chlorpromazine 1968.

Study characteristics
Methods	Randomisation: "randomly assigned”, no further details. Allocation: procedure not described. Blinding: double‐blind, liquid form. no further details. Duration: 24 weeks. Design: parallel. Location: multi‐centre. Setting: inpatient.
Participants	Diagnosis: schizophrenia (clinical diagnosis), continuously hospitalised for at least two years. N = 420. Gender: n.i.. Age: mean 41.6 years. History: duration stable‐ patients were observed on their normal hospital medication for eight weeks, duration ill‐ mean 17.4 years, mean age at first hospitalisation 24.2 years, mean duration of current hospitalisation‐ mean 13.1 years, number of previous hospitalisations‐ n.i., age at onset‐ mean 24.2 years, severity of illness‐ on the average markedly ill, participants were required to show positive or negative symptoms, baseline antipsychotic dose‐ n.i..
Interventions	1. Drug: chlorpromazine. Fixed dose of 300 mg/day. N = 208. *2. Drug: chlorpromazine. Fixed dose of 2000 mg/day (titrated within 45 days, dose reduction to 1500 mg/day was possible). N = 208. 3. Placebo: duration of taper: 0 days. N = 212. *4. Routine treatment (any antipsychotic medication, any dose). N = 210. Rescue medication: n.i., but probably not allowed.
Outcomes	Examined Relapse: a patient was considered relapsed if he regressed and had to be returned to known medication before the end of the 24‐week period. Leaving the study early. Global state: number of participants improved. Death. Adverse effects: based on clinical interview. Unable to use/Not included Mental state: Inpatient Multidimensional Psychiatric Scale, Brief Psychiatric Rating Scale (both only P values/no predefined outcome of interest). Global state: number of participants in remission (no usable data, only reported for a subgroup of patients evaluated by the same rater during the trial). Behaviour: Nurses’ Observation Scale for Inpatient Evaluation (no predefined outcome of interest). Readiness for discharge: Discharge‐Readiness Inventory (no predefined outcome of interest). Ophthalmologic examination (no predefined outcome of interest).
Notes	Quote: *We only analysed the low dose group, because the high dose was excessively high (2000mg chlorpromazine per day) and because the conventional treatment group was not double‐blind.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly assigned, 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, liquid formulation.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double‐blind, liquid formulation.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double‐blind, liquid formulation.
Incomplete outcome data (attrition bias) All outcomes	High risk	Overall 26% dropped out (of which 87% due to relapse). 15% of the participants in the drug group compared to 38% of the participants in the placebo group left the study early. This difference in attrition is a problem for the analysis of other outcomes than relapse.
Selective reporting (reporting bias)	Low risk	No evidence for selective reporting.
Other bias	Low risk	No clear other bias.