Table 1. Baseline characteristics of participants.
| Variable | MD, CBT-E (N=34) | MD, CBT-C (N=34) | MD, WL (N=30) | MD, total (N=98) | HC (N=30) | t or χ2 P-value |
|---|---|---|---|---|---|---|
| Age | 36.9 (10.8) | 37.2 (12.5) | 37.9 (13.5) | 37.3 (12.2) | 37.1 (12.2) | 0.08; 0.939 |
| Female, number (%) | 16 (47.1) | 19 (55.9) | 13 (43.3) | 48 (49) | 15 (50) | 0.01; 0.922 |
| Depressive symptom severity, BDI-II | 27 (9.1) | 27.3 (8.7) | 26.2 (9.9) | 26.9 (9.1) | 4.6 (5.5) | 18.26; <0.001 |
| DSM-IV Axis I comorbidity, number (%) | ||||||
| Anxiety disorders | 8 (23.5) | 7 (20.6) | 8 (26.7) | 23 (23.5) | 0 (0) | 8.58; 0.003 |
| Somatoform disorders | 2 (5.9) | 4 (11.8) | 6 (20) | 12 (12.2) | 0 (0) | 4.05; 0.044 |
| Body mass index, kg/m2 | 25.8 (4.1) | 26.2 (6.3) | 26.5 (5.7) | 26.1 (5.3) | 24 (4.2) | 1.96; 0.052 |
| Education (years) | 11.5 (1.7) | 11.3 (1.7) | 11 (1.7) | 11.3 (1.7) | 12.2 (1.5) | −2.83; 0.006 |
| Number of cigarettes per day | 3.5 (7.3) | 1.5 (4.8) | 4.2 (8.8) | 3 (7.1) | 0.5 (1.9) | 1.90; 0.060 |
| Antidepressant medication, number (%) | 14 (41.2) | 13 (38.2) | 10 (33.3) | 37 (37.8) | 0 (0) | 15.93; <0.001 |
| Physical activity, IPAQ, MET-minutes per week | ||||||
| Walking | 1405 (1646.6) | 1269.9 (1255.9) | 1425.1 (1266.5) | 1364.8 (1392.5) | 1919.5 (2020.6) | −1.61; 0.092 |
| Moderate-intensity activity | 1817.7 (2321) | 2441.9 (2321.3) | 1842.5 (1884.8) | 2040 (2227) | 2243.8 (2813.1) | −0.87; 0.388 |
| Vigorous-intensity activity | 917.5 (1561.1) | 898.2 (1574.4) | 760 (1921.1) | 861.1 (1670.6) | 1577.3 (1739.28) | −2.03; 0.045 |
| CRP, μg ml−1 | 1.4 (1.6) | 1.8 (1.9) | 1.8 (2) | 1.7 (1.8) | 0.8 (0.6) | 4.01; <0.001 |
| CRP ⩾1 μg ml−1, number (%) | 14 (41.2) | 15 (44.1) | 13 (43.3) | 42 (42.9) | 7 (23.3) | 4.39; 0.036 |
| IL-6, pg ml−1 | 4.6 (6.9) | 3.7 (4.3) | 3.6 (3.7) | 3.9 (5.1) | 5.9 (7.8) | −1.22; 0.230 |
| IL-10, pg ml−1 | 6.1 (9.6) | 6.6 (11.1) | 4.8 (6.2) | 5.8 (9.2) | 12.9 (16.3) | −2.09; 0.045 |
| IL-6/IL-10 ratio | 0.9 (0.8) | 0.9 (0.9) | 1.2 (1) | 1 (0.9) | 0.6 (0.4) | 2.71; 0.008 |
| LPS-stimulated IL-6 production, pg ml−1 | 161.3 (153.2) | 163 (116.2) | 217.9 (143) | 183.8 (138.5) | 249.8 (84.1) | −2.89; 0.005 |
| Immune cell counts per μl | ||||||
| Leukocytes | 7070 (2047) | 6013 (1525) | 7303 (1881) | 6780 (1889) | 6740 (2209) | 0.69; 0.924 |
| Lymphocytes | 2193 (764) | 2070 (531) | 2199 (717) | 2152 (669) | 2286 (679) | −0.82; 0.413 |
| Neutrophils | 4319 (1376) | 3479 (1174) | 4535 (1510) | 4099 (1420) | 3520 (989) | 2.15; 0.038 |
| Monocytes | 417 (143) | 373 (134) | 421 (122) | 403 (134) | 310 (153) | 2.78; 0.006 |
| Total T cells | 1510 (616) | 1368 (396) | 1492 (601) | 1454 (541) | 1494 (460) | −0.31; 0.761 |
| T helper cells | 962 (450) | 930 (435) | 954 (412) | 948 (427) | 920 (372) | 0.27; 0.789 |
| Cytotoxic T cells | 464 (247) | 402 (122) | 416 (182) | 426 (188) | 485 (147) | −1.34; 0.184 |
| Regulatory T cells | 83 (38) | 92 (49) | 86 (36) | 87 (41) | 73 (28) | 1.93; 0.061 |
| B cells | 213 (79) | 244 (131) | 248 (137) | 236 (147) | 197 (94) | 1.38; 0.169 |
| NK cells | 256 (152) | 261 (152) | 257 (143) | 258 (147) | 281 (128) | −0.65; 0.516 |
Abbreviations: BDI, Beck Depression Inventory; CBT-C, Cognitive-behavioral therapy control condition; CBT-E, Cognitive-behavioral therapy with exercise; CRP, C-reactive protein; DSM, Diagnostic and Statistical Manual of Mental Disorders; HC, healthy control group; IL, interleukin; IPAQ, International Physical Activity Questionnaire; LPS, lipopolysaccharide; MD, major depression; MET, metabolic equivalent; WL, waitlist control group.
Values are mean (s.d.) unless noted with percentage. Group differences were calculated using χ2 tests for categorical variables and analyses of variance or t-tests for continues variables.