Table 1.
Sample description in participants with major depressive disorder (MDD) compared to healthy controls (HCs)
| Females (n = 109) | Males (n = 66) | Group | Sex | Group × Sex | |||
|---|---|---|---|---|---|---|---|
| MDD (n = 64) | HCs (n = 45) | MDD (n = 39) | HCs (n = 27) | ||||
| Mean (SD) or n (%) | p | p | p | ||||
| Age (years) | 15.22 (1.5) | 15.00 (1.8) | 15.49 (1.4) | 15.00 (1.8) | .15 | .58 | .58 |
| Estimated full‐scale IQ | 106.29 (10.7) | 109.11 (12.1) | 106.47 (9.24) | 102.87 (12.1) | .82 | .08 | .07 |
| Parental educational status a | 3.70 (1.1) | 4.26 (0.9) | 3.41 (1.0) | 3.39 (0.8) | .08 | <.001 | .06 |
| Body mass index | 23.46 (5.1) | 20.68 (3.5) | 24.54 (5.7) | 21.11 (3.1) | <.001 | .13 | .97 |
| Start time Trier Social Stress Test (hr:min) | 15:15 (00:23) | 15:13 (00:32) | 15:08 (00:28) | 15:14 (00:27) | .29 | .20 | .11 |
| Pubertal status a | .10 | <.001 | |||||
| Mid‐pubertal | 1 (1.6) | 4 (8.9) | 13 (27.1) | 15 (55.6) | |||
| Late‐pubertal | 44 (68.8) | 30 (66.7) | 25 (47.9) | 12 (44.4) | |||
| Post‐pubertal | 19 (29.7) | 11 (24.4) | 1 (2.6) | 0 (0.0) | |||
| Current smoking | 27 (42.2) | 2 (4.4) | 9 (23.1) | 3 (11.1) | <.001 | .20 | |
| Any medication | 51 (79.7) | 13 (20.3) | 30 (76.9) | 3 (11.1) | <.001 | .60 | |
| Antipsychotics | 2 (3.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | .02 | .04 | |
| Stimulants | 12 (14.6) | 0 (0.0) | 1 (2.6) | 0 (0.0) | .14 | .88 | |
| Non‐stimulants b | 0 (0.0) | 0 (0.0) | 1 (2.6) | 0 (0.0) | .40 | .20 | |
| SSRIs/antidepressants | 45 (70.3) | 0 (0.0) | 26 (66.7) | 0 (0.0) | <.001 | .81 | |
| Tranquilizer | 2 (3.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | .23 | .27 | |
| Contraceptives | 10 (16.4) | 6 (15.4) | 0 (0.0) | 0 (0.0) | .89 | ||
| Other | 18 (28.1) | 5 (11.1) | 12 (30.8) | 3 (11.1) | <.01 | .80 | |
| Comorbid mental disorders | |||||||
| Lifetime ADHD | 5 (7.8) | 0 (0.0) | 4 (10.3) | 0 (0.0) | .01 | .67 | |
| Lifetime substance use disorder | 0 (0.0) | 0 (0.0) | 4 (10.3) | 0 (0.0) | .09 | <.01 | |
| Lifetime anxiety disorder c | 30 (46.9) | 2 (4.4) | 20 (51.3) | 2 (3.6) | <.001 | .89 | |
| Lifetime PTSD | 9 (14.1) | 1 (2.2) | 2 (5.1) | 1 (3.7) | .05 | .26 | |
| Lifetime eating disorder | 13 (12.6) | 0 (0.0) | 1 (1.0) | 0 (0.0) | <.001 | .01 | |
| Baseline psychoneuroendocrine levels | |||||||
| Psychological stress | 3.05 (3.1) | 1.00 (1.6) | 2.83 (2.6) | 0.80 (1.3) | <.001 | .59 | .98 |
| Cortisol (nmol/L) | 3.66 (1.8) | 3.28 (2.1) | 3.31 (1.7) | 3.03 (1.5) | .25 | .28 | .86 |
| Testosterone (pg/mL) | 45.55 (18.1) | 33.85 (13.4) | 91.4 (43.8) | 58.47 (29.2) | <.001 | <.001 | .01 |
| Oxytocin (pg/mL) | 1.33 (0.3) | 1.57 (0.8) | 1.27 (0.3) | 1.17 (0.8) | .50 | .02 | .09 |
ADHD, attention‐deficit/hyperactivity disorder; PTSD, posttraumatic stress disorder; SSRI, selective serotonin reuptake inhibitor/antidepressant medication.
For definition of parental educational status and pubertal categories, see Appendix S1.
Non‐stimulants include atomoxetine medication ‘Other’ includes asthma medication, painkiller, or vitamin preparation. Participants may have been prescribed more than one medication category.
Rates of lifetime anxiety disorder cover lifetime panic disorder, separation anxiety disorder, avoidant disorder, simple phobia, social phobia, agoraphobia, and overanxious disorder/generalized anxiety disorder.