Dufresne 1993.

Methods	Randomisation: random, no further details. Allocation: procedure not described. Blinding: double, identical capsules. Duration: 6 weeks. Design: parallel. Location: n.i., Setting: n.i.,
Participants	Diagnosis: schizophrenia (DSM‐III). N = 30. Gender: 20 F, 10 M. Age: mean 34 years. History: duration stable ‐ n.i., duration ill ‐ mean 13 years, nr. of prev. hospitalisations ‐ 7, age at onset ‐ mean 21 years, severity of illness ‐ BPRS at baseline 59.9 (SD12.3), baseline antipsychotic dose ‐ n.i.,
Interventions	1. Haloperidol: flexible dose, allowed dose range 5 to 40 mg/day, mean dose n.i.. N = 16. 2. Thioridazine: flexible dose, allowed dose range 100 to 800 mg/day, mean dose N = 14. Other medication: amantadine (antiparkinson medication), chloral hydrate.
Outcomes	Response to treatment: at least 20% reduction in BPRS total score. Leaving the study early. Adverse effects: at least one adverse effect, movement disorders (use of antiparkinson medication), other adverse effects (confusion, dry mouth, hypotension). Unable to use: Mental state: BPRS (incomplete data, no SD). Depression: HAM‐D (incomplete data, no SD). Global state: CGI (incomplete data, no SD). Adverse effects: weight (incomplete data).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised, no further details.
Allocation concealment (selection bias)	Unclear risk	Procedure not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double, identical capsules.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Double, identical capsules.
Incomplete outcome data (attrition bias) All outcomes	High risk	25% of haloperidol participants left the study early. A completers‐only method was used in the study.
Selective reporting (reporting bias)	High risk	No complete data for BPRS and HAM‐D, SDs are missing.
Other bias	Low risk	No clear other bias.