Alprazolam 1992, USA.

Study characteristics
Methods	Allocation: randomised. Blinding: double blind. Design: not stated. Duration: 72 hours. Setting: hospital ‐ psychiatric emergency service, US.
Participants	Diagnosis: all participants fulfilled DSM‐III‐R criteria for schizophrenia. n = 28. Age: mean 33 years. Gender: 11 men, 17 women. Ethnicity: black (n = 23). Consent: gave informed consent. History: not stated. Inclusion: 18‐60 years old, actively psychotic with a minimum score of 12 on the abbreviated BPRS. Exclusion: coexisting major axis disorder, significant medical illness, pregnancy, use of non‐prescription psychoactive drug or alcohol in previous 72 hours.
Interventions	Benzodiazepines plus antipsychotics vs same antipsychotics. 1. Alprazolam 1 mg oral tablet + haloperidol 5 mg oral concentrate, mean 3.2 doses (n = 14). 2. Haloperidol 5 mg oral concentrate + placebo tablet, mean 2.1 doses (n = 14). Repeat dose given within first 24 hours if psychotic subscale was ≥ 11. Total dose administered on day 1 repeated days 2 and 3. Each participant received a minimum of 2 doses.
Outcomes	Global state: no improvement*. Mental state: mean endpoint score (BPRS and BPRS‐psychosis subscale). Adverse effects/events: use of medication for EPS. Hospital and service outcomes: discharged. Unable to use ‐ Global state: level of positive psychiatric symptoms (SAPS); level of negative psychiatric symptoms (SANS) (no data within 48 hours). Adverse effects/events: EPS (no useable data).
Notes	*'Improvement' ‐ undefined; this result included the number of participants who demonstrated lower mean baseline scores on the SAPS and BPRS subscale and were subsequently discharged before the completion of the study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised ‐ participants were 'randomly allocated;' however, no further description of randomisation provided.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind ‐ the investigators who administered the scales were blind to each other's ratings, and trial author DMM was blind to the dose and schedule of treatment. Both investigators were blind to drug assignment. Rating scales: trial author JGB administered the BPRS‐psychosis subscale, SANS, SAPS and trial author DMM administered the full‐scale version of the BPRS ‐ ratings were not a self‐report or completed by an independent rater.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Follow‐up: 69%. 9 participants were permitted to leave the study early for 'humanitarian reasons,' as they had sufficiently improved to allow for early discharge. In this case, a final set of ratings were administered before discharge, and the results were included in the analyses. High attrition rate but last observation carried forward used for the analysis.
Selective reporting (reporting bias)	Unclear risk	Use of Simpson‐Angus Side Effects Profile and 'another side effects rating scale' was mentioned, but no data were reported.
Other bias	Unclear risk	Funding: supported in part by a grant from The Upjohn Company (now Pfizer). We are unsure whether Pfizer were involved in the study design and reporting process.