Dorevitch 1997a.

Methods	Allocation: randomised. Blindness: double‐blind. Duration: 20 weeks total with cross‐over. Parallel period of 8 weeks. Setting: inpatients, Israel. Design: cross‐over study.
Participants	Diagnosis: schizophrenia or schizoaffective (10%) (DSM‐IIR) and TD criteria). N = 40. Sex: 17F 23M. Age: average 64.4 years.
Interventions	1. Vitamin E: 1600 IU. N = 18. 2. Placebo. N = 22. Stable neuroleptic medication: antipsychotics as prescribed.
Outcomes	Leaving the study early. Unable to use: adverse effects (not reported).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No further details.
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	Low risk	Raters blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Two patients did not complete the study and no further details are given.
Selective reporting (reporting bias)	High risk	Not all expected outcomes reported.
Other bias	Low risk	None obvious.