Table 1.
Demographic and clinical characteristics.
| MDD (n = 105) | HC (n = 105) | p-value | |
|---|---|---|---|
| Age (years) | 36.2 ± 13 | 36.4 ± 13 | 0.915 |
| Gender | 0.574 | ||
| Male | 45 (42.9%) | 40 (38.1%) | |
| Female | 60 (57.1%) | 65 (61.9%) | |
| Ethnicity | 0.052 | ||
| Chinese | 86 (81.9%) | 80 (76.2%) | |
| Malay | 10 (9.5%) | 5 (4.8%) | |
| Indian | 7 (6.7%) | 8 (7.6%) | |
| Eurasian | 0 | 3 (2.9%) | |
| Others | 2 (1.9%) | 9 (8.6%) | |
| Handedness † | 0.235 | ||
| Right | 66 (88%) | 89 (90.8%) | |
| Left | 8 (10.7%) | 5 (5.1%) | |
| Ambidextrous | 1 (1.3%) | 4 (4.1%) | |
| Education (years) | 14.8 ± 2.7 | 16.5 ± 1.9 | ≤0.001 |
| Number of words generated | 16.6 ± 6.6 | 20.2 ± 5.7 | ≤0.001 |
| HAM-D | 14.7 ± 7.6 | 2.4 ± 2.3 | ≤0.001 |
| GAF | 68.9 ± 12.5 | 93.4 ± 7.9 | ≤0.001 |
| Family psychiatric history † | 27 (26.5%) | 17 (18.3%) | 0.230 |
| Age at onset (years) | 30.8 ± 11.4 | — | |
| Duration of illness (years) | 5.3 ± 6.5 | — | |
| Past admission to psychiatric ward | 32 (30.5%) | — | |
| Pharmacotherapy | 68 (64.8%) | — | |
| Fluoxetine equivalent dose (mg/day) | 28.9 ± 17.6 | — | |
| Diazepam equivalent dose (mg/day) | 6.2 ± 5 | — | |
| Chlorpromazine equivalent dose (mg/day) | 192.9 ± 132.6 | — |
Mean ± SD are shown and p-values ≤0.05 are in bold.
†Complete demographic data was not obtained for all subjects (Known handedness in healthy controls, n = 98; in major depressive disorder, n = 75. Known family history of psychiatric illness in healthy controls, n = 93; in major depressive disorder, n = 102).