Table 1 Clinical and demographic characteristics
| Â | Major depression | Healthy controls | p values | |
|---|---|---|---|---|
Unipolar | Bipolar | |||
Controls, n | ||||
 Total |  |  | 40 | NA |
 UK |  |  | 32 | |
 Chile |  |  | 8 | |
Unipolar subtype, n | ||||
 Total | 59 |  |  | NA |
 UK | 37 |  |  | |
 Chile | 22 |  |  | |
Bipolar subtype, I/II, n | ||||
 Total |  | 6/6 | NA | NA |
 UK |  | 5/3 | ||
 Chile |  | 1/3 | ||
Atypical/non-atypical depression, n | 24/35 | 3/9 | NA | 0.24λ |
Mean age [years] (SD) | 34 (10.5) | 31.2 (10.6) | 33.2 (8.9) | 0.66 |
M/F | 17/42 | 6/6 | 11/29 | 0.3 |
Episodes; mean (SD) | 2.3 (4.0) | 10.2 (18.7) | 0 (0) | < 0.01 |
Admissions; mean (SD) | 0.1 (0.4) | 0.6 (0.9) | 0 (0) | < 0.01 |
Mean duration of illness [weeks], (SD) | 91.6 (132.9) | 76.6 (151.1) | 0 (0) | < 0.01 |
HAMD-17; mean (SD) | 18.2 (4.6) | 13.0 (6.8) | 0.3 (0.9) | < 0.01 |
QIDS; mean (SD) | 18.2 (4.2) | 15.4 (6.7) | 0.5 (1.4) | < 0.01 |
YMRS; mean (SD) | 1.1 (1.4) | 1.4 (2.7) | 0.1 (0.3) | < 0.01 |