Summary statistics, final study sample
| Characteristic* | MDD (n = 506)† | Healthy controls (n = 358) | p |
|---|---|---|---|
| Sex (male/female), no. | 198/308 | 180/178 | < 0.001 |
| Age, yr | 49.14 ± 7.28 (30.91–65.48) | 52.57 ± 7.94 (35.55–65.61) | 0.014 |
| hsCRP, mg/dL | 0.28 ± 0.41 (0.02–3.80) | 0.17 ± 0.25 (0.02–2.20) | < 0.001 |
| Hamilton Depression Rating Scale, score | 13.74 ± 6.61 (0.00–33.00) | NA | NA |
| Comorbidity index, score | 1.65 ± 0.81 (0.00–5.00) | 0.37 ± 0.61 (0.00–3.00) | < 0.001 |
| Center for Epidemiologic Studies Depression Scale, total score | 27.58 ± 12.16 (0.00–56.00) | 6.3 ± 4.09 (0.00–15.00) | < 0.001 |
| Inpatient episodes, no. | 1.61 ± 1.32 (0.00–10.00) | NA | NA |
| Depressive episodes, no. | 6.22 ± 10.85 (1.00–99.00) | NA | NA |
| Disease duration, mo | 80.71 ± 95.30 (2.00–506.00) | NA | NA |
| Inventory of Depressive Symptomatology, sum score | 3.99 ± 2.86 (0.00–15.00) | NA | NA |
| Body mass index, kg/m2 | 28.41 ± 5.39 (17.70–50.10) | 26.50 ± 3.93 (16.70–41.30) | < 0.001 |
hsCRP = high-sensitivity C-reactive protein; MDD = major depressive disorder; NA = not applicable.
↵* Unless otherwise specified, results are presented as mean ± standard deviation (range); p-values derived from χ2, Mann–Whitney U and t-tests.
↵† In the MDD group, for Hamilton Rating Scale for Depression, n = 504; for comorbidity index, n = 505; for Center for Epidemiologic Studies Depression Scale total, n = 500; for inpatient episodes, n = 498; for depressive episodes, n = 467; for disease duration, n = 501; for Inventory of Depressive Symptomatology sum score, n = 500.