Demographic and clinical characteristics of participants in the 15 studies included in the meta-analysis
| Study | No. participants (female); group | Age, yr; group | Disease state | Illness duration, yr | Severity (scale type) | Mean no. episodes | Statistical threshold | Fraction of patients receiving psychotherapy | Drug status | Nondrug therapy status | Quality scales (out of 12) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MDD | Control | MDD | Control | ||||||||||
| Arnold et al.13 | 17 (14) | 21 (14) | 30 | 27 | Remitted | NA | 9 (HAM-D) | NA | pcorr < 0.001 | NA | Medication-free | NA | 11.5 |
| Choi et al.41 | 54 (26) | 54 (26) | 34 | 34 | Depressed | 7.77 | 19 (HAM-D) | NA | pFWE < 0.05 | NA | Medication-free for ≥ 2 wk | NA | 11 |
| Han et al.26 | 20 (15) | 22 (15) | 43 | 44 | Depressed | 0.3667 | 19 (HAM-D) | FE | pFWE < 0.05 | 0 | Naive | No | 12 |
| Hayashi et al.42 | 30 (13) | 30 (13) | 44 | 44 | Depressed | NA | > 14 (HAM-D) | FE | pFWE < 0.05 | 0 | Naive | No | 11.5 |
| Jia et al.22 | 52 (27) | 52 (28) | 35 | 37 | Depressed | 3.2628 | 23 (HAM-D) | NA | pFWE < 0.05 | 0 | Medication-free for ≥ 2 wk | No | 11.5 |
| Korgaonkar et al.44 | 29 (17) | 39 (21) | 41 | 30 | Depressed | NA | 19 (HAM-D) | NA | pFWE < 0.05 | NA | Medication-free | NA | 10.5 |
| Lai and Wu28 | 44 (23) | 27 (15) | 37 | 38 | Depressed | 0.39 | 22 (HAM-D) | FE | pFWE < 0.05 | 0 | Naive | NA | 11.5 |
| Ma et al.23 | 14 (12) | 14 (12) | 29 | 27 | Depressed | 0.8583 | 38 (BDI) | FE | puncorr < 0.001 | NA | Naive | NA | 11.5 |
| Olvet et al.27 | 52 (31) | 46 (21) | 36 | 30 | Depressed | NA | 19 (HAM-D) | 2 | pFWE < 0.05 | 14/52 | Medication-free for ≥ 2 wk | NA | 10.5 |
| Ouyang et al.15 | 18 (9) | 18 (9) | 27 | 27 | Depressed | 1.2583 | 24 (HAM-D) | FE | puncorr < 0.001 | NA | Naive | No ECT | 11.5 |
| Tha et al.24 | 19 (7) | 19 (6) | 39 | 37 | Depressed | 1.5308 | 19 (HAM-D) | NA | puncorr < 0.001 | NA | Medication-free for ≥ 6 mo | No ECT | 11.5 |
| Wang et al.25 | 21 (16) | 22 (14) | 30 | 30 | Depressed | 1.1833 | 20 (HAM-D) | NA | pASC < 0.05 | 0 | Medication-free for ≥ 4 wk | NA | 11.5 |
| Wu et al.29 | 23 (13) | 21 (12) | 31 | 30 | Depressed | 0.1808 | 22 (HAM-D) | FE | puncorr < 0.001 | 0 | Naive | No ECT | 12 |
| Zhu et al.43 | 25 (15) | 25 (15) | 21 | 20 | Depressed | 0.8617 | 35 (CESD) | FE | pcorr < 0.05 | 0 | Naive | No ECT in the past 6 mo | 12 |
| Zuo et al.30 | 16 (13) | 19 (12) | 37 | 37 | Depressed | NA | 30 (HAM-D) | NA | puncorr < 0.005 | NA | Medication-free for ≥ 2 wk | No ECT | 11.5 |
ASC = AlphaSim correction; BDI = Beck Depression Inventory; CESD = Center for Epidemiologic Studies Depression Scale; ECT = electroconvulsive therapy; FE = first episode; FWE = family-wise error correction; HAM-D = Hamilton Rating Scale for Depression; MDD = major depressive disorder; NA = not available.