Table 1.
Demographic and clinical variables for MDD and healthy control participants
| Healthy controls | MDD participants | MDD D1 | MDD D2 | |
|---|---|---|---|---|
| Sample size | 699 | 685 | 290 | 395 |
| Age (yr) | 38.4 (15.4) | 35.3 (12.3) | 35.3 (12.6) | 35.3 (12.2) |
| Age range (yr) | 16–72 | 18–65 | 18–65 | 18–64 |
| Sex | ||||
| Female (number, percentage) | 404 (58) | 439 (64) | 181 (62) | 258 (65) |
| Male (number, percentage) | 295 (42) | 246 (36) | 109 (38) | 137 (35) |
| Ethnicity (number, percentage) | 621 (89) | 470 (68) | 179 (62) | 290 (73) |
| Asian | 167 (27) | 173 (37) | 80 (45) | 93 (32) |
| Black | 16 (3) | 16 (3) | 2 (1) | 14 (5) |
| Hispanic | 9 (1) | 9 (2) | 1 (0.6) | 8 (3) |
| Middle Eastern | 0 | 2 (0.4) | 1 (1) | 1 (0.3) |
| Mixed | 10 (1.6) | 10 (2) | 2 (0.6) | 8 (3) |
| Native American | 3 (0.4) | 11 (2) | 1 (0.6) | 10 (3) |
| Pacific Islander | 1 (0.2) | 2 (0.4) | 1 (0.6) | 1 (0.3) |
| White | 415 (67) | 247 (53) | 91 (5) | 155 (53) |
| Years of education | 15.3 (2.7) | 14.5 (2.7) | 14.8 (2.5) | 14.4 (2.8) |
| HAM-D | 0.9 (1.5) | 21.4 (5.1) | 21.0 (4.8) | 21.7 (5.3) |
| MADRS | 0.5 (1.1) | 29.0 (5.1) | 28.9 (5.2) | 29.0 (5.0) |
| First-episode/recurrent MDD | 128/355 | 52/168 | 76/187 | |
| Age of onset (yr) | 24.5 (10.8) | 22.5 (9.8) | 25.3 (11.1) | |
| Years of illness | 6.5 (9.9) | 6.3 (8.8) | 6.7 (10.4) | |
| MDD episodes | 7.7 (20.3) | 8.1 (20.8) | 7.4 (20.1) | |
| Duration of current episode (weeks) | 57.9 (119.2) | 55.6 (97.7) | 59.5 (132.2) | |
| Prospective treatment sample | ||||
| Total (number MDD participants) | 359 | 165 | 218 | |
| Escitalopram | 116 | 38 | 102 | |
| Citalopram | 36 | 16 | 20 | |
| Sertraline | 98 | 56 | 42 | |
| Placebo | 109 | 55 | 54 | |
| HAM-D score | ||||
| Baseline | 20.5 (4.1) | 20.0 (4.0) | 20.9 (4.1) | |
Values presented are mean (s.d.) except where indicated. Montgomery–Asberg Depressive Ratings Scale (MADRS) ratings were available from CAN-BIND and Manchester samples. There is a significantly greater number of women than men participants (P = 0.02). Healthy controls had a higher mean age (P = 0.003) and greater number of years of education (P = 5.7 × 10–9) than MDD participants. Chi-squared test of independence was used for the categorical variable (sex), and the Mann–Whitney U test was used for continuous variables (age and years of education). For some sites, the number of years of education was estimated from text data; this is detailed in the Supplementary Information. One healthy control participant was 16 years old, and three were 17 years old. Treatment with SSRI antidepressants showed a significantly greater reduction in HAM-D score (post-treatment HAM-D 10.6) relative to placebo (post-treatment HAM-D 12.5) (t = 2.23, P = 0.03). Ethnicities for Stratifying Resilience and Depression Longitudinally, Oxford, Manchester Remedi, and King’s College London studies (Methods) were estimated to be around 90%, 90%, 90%, and 95% white, respectively.