Akhondzadeh 2005.

Methods	Allocation: randomised. Blindness: double‐blind. Duration: 8 weeks. Setting: hospital, Iran. Design: parallel groups.
Participants	Diagnosis: schizophrenia (DSM‐IV) and PANSS > 59 criteria). N = 46. Sex: 13 female, 33 male. Age: average 33.8 (selegiline), 35.0 (placebo)
Interventions	1. Allopurinol: 300mg. N = 23. 2. Placebo. N = 23. Stable neuroleptic medication: haloperidol 15 mg.
Outcomes	Leaving the study early. Mental state: PANSS change score. Adverse events: various specific effects.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated.
Allocation concealment (selection bias)	Unclear risk	No further details.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No further details.
Incomplete outcome data (attrition bias) All outcomes	Low risk	LOCF analysis reported.
Selective reporting (reporting bias)	Low risk	Main outcomes reported.
Other bias	Low risk	None obvious.