Table 2.
Prevalence of depressive symptoms (BDI-II > 13) according to adolescents’ characteristics for girls and boys (Porto, Portugal 2003–2004) (n = 1,988).
| Girls (n = 1,037) n (%) |
Boys (n = 951) n (%) |
||||||
|---|---|---|---|---|---|---|---|
| Characteristics | BDI-II ≤ 13 | BDI-II > 13 | p-value ‡ | BDI-II ≤ 13 | BDI-II > 13 | p-value ‡ | |
| Family characteristics | |||||||
| Parents’ education, year | |||||||
| 0–6 | 226 (27.6) | 63 (34.4) | 0.199 | 191 (22.7) | 24 (38.7) | 0.029 | |
| 7–9 | 168 (20.5) | 40 (21.9) | 174 (20.6) | 8 (12.9) | |||
| 10–12 | 211 (25.8) | 42 (23.0) | 235 (27.9) | 13 (21.0) | |||
| ≥13 | 213 (26.0) | 38 (20.8) | 243 (28.8) | 17 (27.4) | |||
| Household | |||||||
| Both parents | 632 (75.1) | 140 (72.2) | 0.390 | 696 (79.3) | 50 (69.4) | 0.051 | |
| Mother/father/other | 209 (24.9) | 54 (27.8) | 182 (20.7) | 22 (30.6) | |||
| Parents’ depression | |||||||
| None | 291 (56.7) | 54 (50.5) | 0.256 | 297 (57.4) | 13 (41.9) | 0.146 | |
| At least 1 parent | 164 (32.0) | 43 (40.2) | 163 (31.5) | 15 (48.4) | |||
| Do not know | 58 (11.3) | 10 (9.3) | 57 (11.0) | 3 (9.7) | |||
| Individual characteristics | |||||||
| Age at menarche, year | |||||||
| ≤10 | 65 (8.1) | 26 (14.2) | 0.026 | ||||
| 11 | 178 (22.2) | 45 (24.6) | |||||
| 12 | 281 (35.1) | 66 (36.1) | |||||
| ≥13 | 148 (18.5) | 28 (15.3) | |||||
| Pre-menarche | 128 (16.0) | 18 (9.8) | |||||
| BMI † | |||||||
| <p85 | 622 (74.4) | 147 (76.2) | 0.338 | 623 (71.5) | 56 (78.9) | 0.414 | |
| ≥p85 & < p95 | 140 (16.7) | 25 (13.0) | 147 (16.9) | 9 (12.7) | |||
| ≥p95 | 74 (8.9) | 21 (10.9) | 101 (11.6) | 6 (8.5) | |||
| Sleeping duration, h | |||||||
| 8.5–9.5 | 305 (40.0) | 61 (34.5) | 0.298 | 311 (41.4) | 15 (31.2) | 0.367 | |
| ≥9.5 | 223 (29.2) | 52 (29.4) | 243 (32.4) | 19 (39.6) | |||
| ≤8.5 | 235 (30.8) | 64 (36.2) | 197 (26.2) | 14 (29.2) | |||
| Behaviours | |||||||
| Smoking | |||||||
| Never | 640 (76.8) | 111 (57.5) | <0.001 | 697 (81.8) | 51 (71.8) | 0.039 | |
| Ever | 193 (23.2) | 82 (42.5) | 155 (18.2) | 20 (28.2) | |||
| Drinking alcohol | |||||||
| Never | 385 (46.2) | 71 (37.6) | 0.032 | 413 (48.0) | 31 (44.3) | 0.553 | |
| Ever | 449 (53.8) | 118 (62.4) | 448 (52.0) | 39 (55.7) | |||
| Physical exercise | |||||||
| Never | 490 (59.3) | 125 (65.8) | 0.240 | 335 (38.7) | 30 (44.1) | 0.028 | |
| ≤1 time/week | 120 (14.5) | 21 (11.1) | 117 (13.5) | 5 (7.4) | |||
| 2–3 times/week | 171 (20.7) | 38 (20.0) | 301 (34.8) | 17 (25.0) | |||
| ≥4 times/week | 46 (5.6) | 6 (3.2) | 113 (13.0) | 16 (23.5) | |||
Abbreviations: BDI-II, Beck Depression Inventory, Second Edition; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared). † BMI was classified according to the age- and sex-specific BMI percentiles, elaborated by the United States Centers for Disease Control and Prevention. ‡ Chi-Square test.