Table 1.
Baseline demographics and clinical characteristics of participants
| Ketamine group (n=33) | Saline group (n=37) | ||
|---|---|---|---|
| Mean age, years | 52·5 (11·9) | 56·4 (12·4) | |
| Sex, female | 22 (67%) | 22 (60%) | |
| Mean years in full-time education | 13·7 (4·0) | 13·5 (3·2) | |
| Ethnicity white | 31 (94%) | 35 (95%) | |
| Married or current partner | 13 (39%) | 19 (51%) | |
| Mean IQ | 105·1 (11·3) | 109·9 (11·0) | |
| MMSE | 28·8 (2·0) | 29·0 (1·2) | |
| Illness characteristics | |||
| Inpatient | 11 (33%) | 21 (57%) | |
| Bipolar disorder | 4 (12%) | 7 (19%) | |
| Age of onset (years) | 29·6 (14·0) | 32·2 (17·0) | |
| Number of depressive episodes (lifetime) | 4·9 (4·4) | 5·3 (5·2) | |
| Number of hypomanic/manic episodes | 0·3 (1·0) | 0·5 (1·8) | |
| Previous ECT | 18 (55%) | 16 (43%) | |
| Family history of depression | 23 (70%) | 18 (49%) | |
| Family history of bipolar disorder | 2 (6%) | 10 (27%) | |
| Current depressive episode | |||
| MADRS score | 31·8 (7·4) | 35·2 (8·4) | |
| Melancholia no psychosis | 26 (79%) | 25 (68%) | |
| Psychosis ± melancholia | 3 (9%) | 8 (22%) | |
| Median duration, months | 14 (7–38) | 8 (3·5–20·5) | |
| MGHS score | 4·8 (2·6) | 4·0 (3·4) | |
| Comorbidity | |||
| Anxiety disorder or secondary OCD | 16 (48%) | 18 (49%) | |
| Other psychiatric disorder | 1 (3%) | 0 (0%) | |
| Medical illness | 12 (36%) | 9 (24%) | |
| Physical signs | |||
| Weight, kg | 82·2 (17·1) | 77·2 (17·7) | |
| BMI, kg/m2 | 29·3 (5·8) | 28·8 (6·7) | |
| Systolic blood pressure, mmHg | 132·9 (18·0) | 126·1 (17·2) | |
| Psychotropic medication | |||
| SSRI | 10 (30%) | 14 (38%) | |
| SNRI | 16 (48%) | 15 (41%) | |
| TCA | 4 (12%) | 8 (22%) | |
| MAOI | 0 (0) | 1 (3%) | |
| Other antidepressant | 14 (42%) | 10 (27%) | |
| Antipsychotic | 18 (55%) | 26 (70%) | |
| Lithium | 7 (21%) | 5 (14%) | |
| Antiepileptic mood stabiliser | 5 (15%) | 7 (19%) | |
| Hypnotic/anxiolytic | 17 (52%) | 21 (57%) | |
Data are mean (SD), n (%), or median (IQR). BMI=body-mass index. IQ=intelligence quotient. MAOI=monoamine oxidase inhibitor. MGHS=Massachusetts General Hospital Scale. MMSE=Mini Mental State Examination. OCD=obsessive compulsive disorder. SNRI=serotonin and noradrenaline reuptake inhibitor. SSRI=selective serotonin reuptake inhibitor. TCA=tricyclic antidepressant.