TABLE 1.
Baseline descriptive and clinical characteristics of primary sample
| Ketamine group (n = 36) | Midazolam group (n = 21) | |
|---|---|---|
| Age, mean (SD), y | 48.6 (11.4) | 43.8 (10.9) |
| Female, No. (%) | 20 (56%) | 10 (48%) |
| Non-Hispanic Caucasian, No. (%) | 22 (61%) | 16 (76%) |
| Mini mental status examination, mean (SD) | 29.6 (0.9) | 29.6 (0.5) |
| Median education level, y | 14 | 16 |
| Time since illness onset, mean (SD), y | 24.3 (12.4) | 21.5 (15.3) |
| Age-of-onset, mean (SD), y | 22.9 (9.6) | 20.4 (10.4) |
| Number of episodes, mean (SD) | 1.9 (1.7) | 2.3 (2.1) |
| Duration of current episode, mean (SD), y | 11.6 (14.3) | 7.8 (8.8) |
| Number of failed antidepressant trials in current episode, mean (SD) | 5.1 (1.9) | 5.4 (1.9) |
| History of suicide attempts, No. (%) | 10 (28%) | 8 (38%) |
| MADRS total score (baseline), mean (SD) | 33.3 (5.6) | 32.4 (4.8) |
| QIDS total score (baseline), mean (SD) | 16.6 (4.2) | 16.5 (4.7) |
| BSS, mean (SD) | 6.1 (6.8) | 6.2 (6.7) |
| BSS score ≥ 4, No. (%) | 19 (52.8%) | 11 (52.4%) |
| All suicidal indices = 0, No. (%) | 4 (11.1%) | 0 (0%) |
Note: Groups do not differ significantly on any variable according to unpaired t-tests (continuous variables; Ps > .13) and χ2 tests (categorical variables; Ps > .25). MADRS, Montgomery-Asberg depression rating scale (16); QIDS, quick inventory of depressive symptoms (self-report); BSS, Beck scale for suicide ideation; “All suicidal indices” includes MADRS and QIDS suicide items and BSS.