C +CPZ 1999.

Methods	Allocation: 'randomised' according to hospital admission order. Blinding: not stated. Duration: 6 weeks. Setting: inpatients. Design: parallel. Country: China.
Participants	Diagnosis: schizophrenia (CCMD‐2‐R). N = 115. Age: mean ˜ 28 years, SD ˜ 10 years. Sex: male and female. History: length of illness mean ˜ 11 months, SD ˜ 9 months.
Interventions	Monotherapy: chlorpromazine (400 mg/day) (N = 35). Monotherapy: clozapine (300 mg/day) (N = 40). Combination therapy: chlorpromazine (100 mg/day)+ clozapine (300 mg/day) (N = 40).
Outcomes	‐ Usable data ‐ Mental state: BPRS. Adverse events: TESS.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	'Randomised' according to hospital admission order, but no further information.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not stated.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No incomplete outcome data.
Selective reporting (reporting bias)	Low risk	All measured outcomes were reported.
Other bias	Low risk	None obvious.