Schiele 1969.

Methods	Allocation: randomly assigned (by administrative personnel not involved with patient treatment or evaluation). Blindness: double (identical capsules). Design: 2 parallel groups. Duration: 4 weeks, but it was permitted to remove patients at the end of 2 weeks or to continue beyond the 4 weeks. Analysis: only 2 weeks ratings were analysed because of the small sample size. Country: USA.
Participants	Diagnosis: schizophrenia, no further information. N=21. Age: range 16‐48 years, mean 24 years. Sex: no information. Setting: hospital. History: acute illness; patients must not have been hospitalised during the preceding 12 months, or have childhood schizophrenia, or brain syndrome, or mental deficiency, alcoholism, epilepsy or drug addiction.
Interventions	1. Trifluoperazine: range 15‐30 mg/day. N=10. 2. Trifluperidol: range 3‐6 mg/day. N=11. Without washout period; using antiparkinson drug only if dose reduction of the antipsychotic did not provide relief.
Outcomes	Leaving the study early (at the end of 2 weeks). Unable to use ‐ Global state: (Global rating of Pathology; Global rating of improvement ‐ no SD). Mental state: (BPRS; MMPI; IMPS ‐ no SD). Side effects: (no data available).
Notes	# Analysis performed in 2 weeks.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate