Berman 2000.

Study characteristics
Methods	Double‐blind randomised controlled cross‐over trial
Participants	Diagnosis: DSM‐IV major depressive episode (1 bipolar disorder, depressed) N: 9 Age: M = 37 (SD = 10.0) Sex: 56% female Baseline depression severity: ketamine group HRSD = 33.0 (SD = 6.7); placebo group HRSD = 26.9 (SD = 5.8)
Interventions	1 single IV infusion Ketamine (N = 4) 0.5 mg/kg infused over 40 minutes Placebo (N = 3) saline solution infused over 40 minutes Concomitant treatment: no, patients had a 2‐week drug‐free period before commencing treatment
Outcomes	HRSD Response rate (≥50% reduction in HRSD scores) BDI VAS BPRS
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details given on randomisation procedure beyond quote: ''four participants were randomly assigned''
Allocation concealment (selection bias)	Unclear risk	No details given on allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No details given on blinding beyond quote: '''in a randomised, double‐blinded manner''
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details given on blinding of outcome assessment
Incomplete outcome data (attrition bias) All outcomes	High risk	2/9 participants withdrew to institute antidepressant treatment
Selective reporting (reporting bias)	High risk	Scores not reported for each measured time point (only baseline and final) and BDI scores missing
Other bias	Low risk	No other potential sources of bias identified