Table 1.
Summary of the study characteristics in the current meta-analysis
| Study | Diagnostic criteria | Subjects | N | Sex (% female) | Mean age (years) | Severity of disease | Duration of illness (years) | Drug-free | NGF source | NGF measurement | NGF value (pg/mL) | Country |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bilgen et al25 | DSM-IV | MDD HC |
30 30 |
65 | 32.1±5.8 | 30.7±4.1 (HAM-D) | NA | Yes | Serum | ELISA | 399.4±91.7 524.1±76.7 |
Turkey |
| de Azevedo Cardoso et al30 | DSM-IV | MDD HC |
120 120 |
79.2 | 23.8±3.3 | 12.2±3.7 (HAM-D) | 5.8±4.9 | Yes | Serum | ELISA | 153.9±158.0 93.4±32.0 |
Brazil |
| Liu et al31 | DSM-IV | Depression HC |
30 50 |
37.5 | 40.8±12.8 | 28.0±8.1 (HAM-D) | NA | Yes | Serum | ELISA | 33.2±7.4 36.3±15.1 |
People’s Republic of China |
| Diniz et al27 | DSM-IV | MDD remit MDD severe HC |
17 38 22 |
75.3 | NA | NA | NA | Yes | Serum | ELISA | 16.9 (8.9–24.5) 15.4 (17.8–20.1) 38.1 (14.3–65.8)* |
Brazil |
| Martino et al28 | DSM-IV | MDD HC |
30 32 |
77.4 | 46.7±10.8 | 21.6±3.7 (HAM-D) | NA | Yes | Serum | ELISA | 202.1±70.1 263.6±80.6 |
Italy |
| Pallavi et al22 | DSM-IV | Depression HC |
84 64 |
42.6 | 15.5±1.8 | 30 (BDI) | NA | No | Serum | ELISA | 5,910.5±1,590.8 6,723.9±1,098.8 |
India |
| Hellweg et al33 | DSM-IV | MDD | 40 | 77.5 | 50.6±14.4 | 23.2±4.58 (HAM-D) | NA | No | Serum | ELISA | 33.5±75.5 | Germany |
| Ziegenhorn et al29 | DSM-III-R | Depression HC |
27 107 |
50.9 | NA | NA | NA | No | Serum | ELISA | 18.0±4.1 22.9±4.8 |
Germany |
Notes: Data are presented as the mean ± standard deviation.
*
Median (25th–75th percentile).
Abbreviations: N, number; NGF, nerve growth factor; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; MDD, major depressive disorder; HC, healthy control; HAM-D, Hamilton Depression Rating Scale; NA, not available; ELISA, enzyme-linked immunosorbent assay; BDI, Beck Depression Inventory; DSM-III-R, Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition, Revised.