Methods	Allocation: random, computer-generated randomisation. Blindness: double, identical capsules. Duration: 24 weeks. Design: parallel. Location: multicentre. Countries: Belgium, Czech Republic, Denmark, France, Hungary, Morocco, Portugal, UK, Switzerland, Tunisia
Participants	Diagnosis: (DSM-IV) schizophrenia disorganised (n=33), paranoid (n=260) or undifferentiated (n=76) or schizophreniform disorder (n=8), dominant positive symptoms, BPRS of 36 or more, PANSS positive score higher than PANSS negative score. N=377. Age: 18-65 years (mean amisulpride=38.2 years, mean olanzapine=37.4 years). Sex: 245 M, 132 F. History: duration ill mean amisulpride=9.56 years, mean olanzapine=8.12 years, age at onset, not described. Setting: in- and outpatient.
Interventions	Amisulpride: flexible dose. Allowed dose range: 200-800 mg/day. Mean dose: 504 mg/day. N=189 Olanzapine: flexible dose. Allowed dose range: 5-20 mg/day. Mean dose: 13 mg/day. N=188
Outcomes	Leaving the study early: any reason, adverse events, inefficacy. Global State: CGI. Mental State: PANSS total score, BPRS total score, PANSS positive subscore, PANSS negative subscore, Depression MADRS. General Functioning: SOFAS total score. Quality of life: QLS total score. Adverse effects: open interviews, cardiac effects (ECG), death (natural causes, suicide) EPS (akathisia, dystonia, parkinsonism, use of antiparkinson medication, AIMS, Simpson-Angus), glucose, sedation, weight Unable to use - Amenorrhoea (no data).
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Adequate sequence generation?	Low risk	Random, computer-generated randomisation.
Allocation concealment?	Low risk	Computer generated randomisation list was prepared and kept outside the study centre. Quote: Patient numbers were assigned in strict chronological order in each centre
Blinding? Objective outcomes	Low risk	Objective outcomes such as laboratory measures or death are unlikely to have been much affected by problems of blinding
Blinding? Subjective outcomes	Unclear risk	Double, identical capsules. Quote: “to permit dose adjustment whilst maintaining the double-blind, blister packs corresponding to a low and a high dosage were provided”. Whether blinding was successful has not been examined, but both compounds differ quite substantially in side-effects. This can be a problem for blinding
Incomplete outcome data addressed? All outcomes	High risk	The rate of leaving the study early was high (35.8%). The last-observation-carried-forward method was used to account for people leaving the study early. It assumes that a participant who discontinued the study would not have had a change of his condition if he had remained in the study. This assumption can obviously be wrong. It is unclear whether this led to bias
Free of selective reporting?	High risk	Only those adverse events that occurred in at least 5% of the participants were reported. This procedure can miss rare, but important adverse events
Free of other bias?	High risk	The study was sponsored by the manufacturer of amisulpride.