Penfluridol 1987.

Study characteristics
Methods	Randomisation: n.i., but double‐blind study. Allocation: procedure not described. Blinding: double‐blind, identical capsules. Duration: 12 weeks. Design: parallel. Location: single‐centre. Setting: unclear.
Participants	Diagnosis: chronic schizophrenia (DSM‐III), all on maintenance medication for control of continuous symptoms, all stable for at least 6 months. N = 30. Gender: 16 men, 12 women. Age: mean 36.0 years. History: duration stable‐ at least 6 months, duration ill‐ mean 11.1 years, number of previous hospitalisations‐ n.i., age at onset‐ 24.9 years, severity of illness‐ n.i., baseline antipsychotic dose‐ mean 297.5 mg/day chlorpromazine equivalent.
Interventions	1. Drug: penfluridol. Fixed dose of 55 mg/week. N = 15. 2. Placebo: duration of taper: 0 days. N = 15. Rescue medication: antiparkinson medication and haloperidol, but this was considered to be a relapse.
Outcomes	Examined Relapse (need of additional haloperidol medication). Leaving the study early. Unable to use/Not included Mental state (Scale for the Assessment of Positive Symptoms and Negative Symptoms ‐ no data /no predefined outcome of interest). Adverse effects: extrapyramidal side‐effects (Simpson Angus Scale (SAS) ‐ no data / continuous side‐effect results were not among the prespecified outcomes). Physiological measures: mean body weight, pulse rate, blood pressure, laboratory (all no data/no prespecified outcomes of interest).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	N.i., but double‐blind study.
Allocation concealment (selection bias)	Unclear risk	Procedure not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double, identical capsules.
Blinding (performance bias and detection bias) Subjective outcomes	Unclear risk	Double, identical capsules.
Blinding (performance bias and detection bias) Objective outcomes	Low risk	Double, identical capsules.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only study completers were used in the final analysis, but as there were only two dropouts (one in each group) this was not necessarily a problem.
Selective reporting (reporting bias)	Low risk	Rating scale results were not reported, but these were not of interest for the review.
Other bias	Low risk	No clear evidence for other bias.