Zarate 2006b.

Study characteristics
Methods	Double‐blind randomised controlled trial
Participants	Diagnosis: DSM‐IV major depressive disorder; MADRS score ≥ 22 N: 32 Age: memantine group M = 47.1 (SD = 12.3); placebo group M = 46.1 (SD = 9.4) Sex: memantine group 56% female; placebo group 44% female Baseline depression severity: memantine group MADRS = 30.23; placebo group MADRS = 31.73
Interventions	8 weeks of treatment Memantine (N = 16) gradually titrated: 5 mg/day and increased by 5 mg/week as tolerated up to a maximum of 20 mg/day Placebo (N =16) Concomitant treatment: zopidem 5 mg to 0 mg/day as needed for insomnia (no more than three times per week and not within 8 hours of ratings). No other psychotropic medication allowed
Outcomes	MADRS Response rate (not defined) CGI HAMA
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: ''Randomly assigned'' no further information given
Allocation concealment (selection bias)	Unclear risk	No details given on allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: ''Double‐blind'' no further information given
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: ''Double‐blind'' no further information given
Incomplete outcome data (attrition bias) All outcomes	Low risk	Study reports dropouts
Selective reporting (reporting bias)	Unclear risk	Protocol unavailable. Data reported matches methods
Other bias	Low risk	No other potential sources of bias identified