Demographic and clinical characteristics of the study groups and statistical significance of group differences
| Group | No. | Age, mean (SD) [range] yr | Sex, no. female:male | Test, mean (SD) score | Age at onset, mean (SD) yr | Cumulative illness duration, mean (SD) yr | No. admissions to hospital, mean (SD) | ||
|---|---|---|---|---|---|---|---|---|---|
| HAM-D | MADRS | BDI II | |||||||
| MDD-FHP | 30 | 40.7 (9.0) [24–57] | 19:11 | 29.0 (6.5) | 30.7 (6.6) | 34.7 (11.9) | 23.6 (10.6) | 9.4 (9.3) | 0.4 (0.7) |
| MDD-FHN | 20 | 45.7 (12.5) [23–64] | 14:6 | 28.1 (6.6) | 28.5 (7.3) | 30.3 (11.7) | 27.4 (15.3) | 9.6 (13.4) | 1.3 (4.9) |
| HC-FHP | 21 | 38.6 (14.5) [21–65] | 11:10 | 3.7 (3.1) | 3.1 (4) | 3.7 (5.7) | — | — | — |
| HC-FHN | 25 | 36.3 (11.9) [21–65] | 13:12 | 1.8 (1.9) | 0.5 (1.7) | 2.04 (2.5) | — | — | — |
| p value of the intergroup difference | 0.07 | 0.55 | < 0.001* | < 0.001* | < 0.001* | 0.33 | 0.93 | 0.31 | |
BDI II = Beck Depression Inventory II;38 HAM-D = Hamilton Rating Scale for Depression;36 HC-FHN = healthy controls without family history of MDD; HC-FHP = healthy controls with a family history of MDD; MADRS = Montgomery-Åsberg Depression Rating Scale;37 MDD = major depressive disorder; MDD-FHN = patients with MDD without family history of MD; MDD-FHP = patients with MDD with a family history of MDD; SD = standard deviation.
↵* Significant differences between patients with major depressive disorder (MDD-FHN, MDD-FHP) and healthy controls (HC-FHP, HC-FHN); 4-group factorial analysis of variance was used for age and depression ratings; χ2 was applied for sex.