Chlorpromazine 1973.

Study characteristics
Methods	Randomisation: randomly assigned, no further details. Allocation: procedure not described. Blinding: double‐blind, identical capsules, no further details. Duration: 2 to 3 years (data available up to 2 years). Design: parallel. Location: three centres. Setting: outpatient.
Participants	Diagnosis: schizophrenia (DSM‐II, undifferentiated type 46.3%, paranoid 39%, acute differentiated 8%, schizoid affective 2.7%, other 3.8%), currently hospitalised for less than 2 years. N = 374. Gender: 159 men, 215 women. Age: mean 34.4 years. History: duration stable‐ 2 months transition phase, those who relapsed during this time were replaced, duration ill‐ n.i., number of previous hospitalisations‐ mean 2.6, age at onset‐ n.i., severity of illness‐ n.i., baseline antipsychotic dose‐ mean 265mg chlorpromazine per day.
Interventions	Previous medication was gradually shifted to chlorpromazine for two months. 1. Drug: chlorpromazine ‐ Flexible dose. Allowed dose range: 100 mg/day. Mean dose: ~ 260 mg/day. N = 192. 2. Placebo: duration of taper: 0 days. N = 182. Rescue medication: not indicated, but probably not allowed.
Outcomes	Examined Relapse: clinical deterioration of such magnitude that hospitalisation appeared imminent. Service use: number of participants hospitalised. Unable to use/Not included Leaving the study early (numbers not specified for each group separately). Mental state: Brief Psychiatric Rating Scale, Inpatient Multidimensional Psychiatric Scale, Springfield Symptom Index, Hopkin’s Symptom Distress Check List (all no SDs and data only given for subgroups/no predefined outcome of interest). Social behaviour and adjustment: Katz Adjustment Scale, Major Role Adjustment Inventory (no usable data). Number of participants employed (no usable data).
Notes	Half of the participants randomly received major role therapy in addition to chlorpromazine or placebo. For the purpose of this review the four resulting groups were pooled as described above.
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, identical capsules, no further details.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double‐blind, identical capsules, no further details.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double‐blind, identical capsules, no further details.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Relatively few participants left the study early due to reasons other than relapse which was the only outcome (n = 31). Although it is unclear in which group they occurred the small percentage does not represent an important risk of bias.
Selective reporting (reporting bias)	Low risk	No clear evidence for selective reporting.
Other bias	Low risk	No clear other bias.