Table 2.
Subject characteristics and Hamilton Depression Rating Scale (HAMD 17‐item) scores by severity index for the validation samples
| Variable | MDD (N = 83) | Severe MDD (N = 32) | Mild MDD (N = 51) | Healthy control (N = 25) | p values | p value for severe versus mild | p value for severe versus HC | p value for mild versus HC |
|---|---|---|---|---|---|---|---|---|
| Male | 32 (38.55%) | 10 (31.25%) | 28 (54.9%) | 12 (48%) | .3944 | – | – | – |
| Age (years) | 35.66 ± 12.44 | 34.94 ± 12.48 | 36.12 ± 12.52 | 33.72 ± 13.43 | .7484 | – | – | – |
| Left handedness | 10 (12.05%) | 2 (6.25%) | 8 (15.69%) | 2 (8%) | .0624 | – | – | – |
| Right handedness | 69 (83.13%) | 26 (81.25%) | 43 (84.31%) | 22 (88%) | ||||
| HAMD | 18.76 ± 4.50 | 23.59 ± 2.38 | 15.73 ± 2.30 | 1.28 ± 2.01 | <.0001 | <.0001 | <.0001 | <.0001 |
|
Factor 1 Psychic depression (max = 11.05) |
6.70 ± 1.82 | 7.47 ± 1.72 | 6.21 ± 1.73 | 0.18 ± 0.35 | <.0001 | .0004 | <.0001 | <.0001 |
|
Factor 2 Motivation (max = 5.84) |
2.35 ± 1.13 | 3.16 ± 1.08 | 1.85 ± 0.83 | 0.02 ± 0.10 | <.0001 | <.0001 | <.0001 | <.0001 |
|
Factor 3 Psychosis (max = 2.18) |
0.30 ± 0.50 | 0.37 ± 0.50 | 0.25 ± 0.50 | 0.00 ± 0.00 | 0.3138 | – | – | – |
|
Factor 4 Anxiety (max = 6.32) |
2.49 ± 1.21 | 3.35 ± 1.23 | 1.95 ± 0.83 | 0.31 ± 0.45 | <.0001 | <.0001 | <.0001 | <.0001 |
|
Factor 5 Sleep (max = 4.32) |
2.24 ± 1.28 | 2.99 ± 1.00 | 1.77 ± 1.21 | 0.25 ± 0.63 | <.0001 | <.0001 | <.0001 | .0001 |
MDD = major depressive disorder; HC = healthy controls.
Notes. p values were based on anova comparing severe MDD, mild MDD, and HC. For those variables that had significant differences among three groups, all pair‐wise comparisons were still significant except that there was no significant age difference between mild MDD and HC.