TABLE 1.
Item level sample characteristics.
| Age quantiles | Overall | (12–13] | (13–19] | (19–24] | (24–27) |
|---|---|---|---|---|---|
| n | 3797 | 950 | 949 | 949 | 949 |
| Sex = M (%) | 1709 (45.0) | 460 (48.4) | 442 (46.6) | 404 (42.6) | 403 (42.5) |
| Age (mean [SD]) | 18.28 (4.87) | 12.93 (0.26) | 15.57 (2.83) | 19.50 (1.28) | 25.14 (0.78) |
| Zygosity MZ (%) | 1764 (46.5) | 375 (39.5) | 444 (46.8) | 435 (45.8) | 510 (53.7) |
| Household income € (mean [SD]) | 4070.23 (3178.78) | 4694.36 (2843.80) | 4268.23 (3452.42) | 4048.50 (2732.16) | 3270.00 (3421.02) |
| Depressive symptoms items | |||||
| I am sad (%) | |||||
| 1 Never | 925 (24.4) | 240 (25.3) | 247 (26.0) | 207 (21.8) | 231 (24.3) |
| 2 | 1991 (52.4) | 539 (56.7) | 515 (54.3) | 470 (49.5) | 467 (49.2) |
| 3 | 446 (11.7) | 87 (9.2) | 98 (10.3) | 125 (13.2) | 136 (14.3) |
| 4 Always | 57 (1.5) | 9 (0.9) | 14 (1.5) | 15 (1.6) | 19 (2.0) |
| NA | 378 (10.0) | 75 (7.9) | 75 (7.9) | 132 (13.9) | 96 (10.1) |
| I am pessimistic about my future (%) | |||||
| 1 Never | 1933 (50.9) | 530 (55.8) | 467 (49.2) | 439 (46.3) | 497 (52.4) |
| 2 | 1042 (27.4) | 233 (24.5) | 278 (29.3) | 268 (28.2) | 263 (27.7) |
| 3 | 327 (8.6) | 73 (7.7) | 90 (9.5) | 87 (9.2) | 77 (8.1) |
| 4 Always | 61 (1.6) | 19 (2.0) | 15 (1.6) | 14 (1.5) | 13 (1.4) |
| NA | 434 (11.4) | 95 (10.0) | 99 (10.4) | 141 (14.9) | 99 (10.4) |
| I feel like a failure (%) | |||||
| 1 Never | 2373 (62.5) | 652 (68.6) | 610 (64.3) | 527 (55.5) | 584 (61.5) |
| 2 | 800 (21.1) | 172 (18.1) | 204 (21.5) | 225 (23.7) | 199 (21.0) |
| 3 | 214 (5.6) | 47 (4.9) | 51 (5.4) | 53 (5.6) | 63 (6.6) |
| 4 Always | 43 (1.1) | 10 (1.1) | 8 (0.8) | 17 (1.8) | 8 (0.8) |
| NA | 367 (9.7) | 69 (7.3) | 76 (8.0) | 127 (13.4) | 95 (10.0) |
| Difficult to enjoy anything (%) | |||||
| 1 Never | 1879 (49.5) | 568 (59.8) | 514 (54.2) | 419 (44.2) | 378 (39.8) |
| 2 | 1072 (28.2) | 235 (24.7) | 258 (27.2) | 266 (28.0) | 313 (33.0) |
| 3 | 378 (10.0) | 66 (6.9) | 77 (8.1) | 104 (11.0) | 131 (13.8) |
| 4 Always | 90 (2.4) | 10 (1.1) | 20 (2.1) | 28 (3.0) | 32 (3.4) |
| NA | 378 (10.0) | 71 (7.5) | 80 (8.4) | 132 (13.9) | 95 (10.0) |
| Disappointed in myself (%) | |||||
| 1 Never | 1599 (42.1) | 445 (46.8) | 404 (42.6) | 356 (37.5) | 394 (41.5) |
| 2 | 1387 (36.5) | 355 (37.4) | 362 (38.1) | 321 (33.8) | 349 (36.8) |
| 3 | 379 (10.0) | 67 (7.1) | 97 (10.2) | 123 (13.0) | 92 (9.7) |
| 4 Always | 59 (1.6) | 15 (1.6) | 11 (1.2) | 17 (1.8) | 16 (1.7) |
| NA | 373 (9.8) | 68 (7.2) | 75 (7.9) | 132 (13.9) | 98 (10.3) |
| Blame myself for mistakes and weaknesses (%) | |||||
| 1 Never | 1204 (31.7) | 400 (42.1) | 345 (36.4) | 223 (23.5) | 236 (24.9) |
| 2 | 1400 (36.9) | 338 (35.6) | 346 (36.5) | 345 (36.4) | 371 (39.1) |
| 3 | 659 (17.4) | 118 (12.4) | 142 (15.0) | 192 (20.2) | 207 (21.8) |
| 4 Always | 151 (4.0) | 22 (2.3) | 35 (3.7) | 56 (5.9) | 38 (4.0) |
| NA | 383 (10.1) | 72 (7.6) | 81 (8.5) | 133 (14.0) | 97 (10.2) |
| Think about hurting myself (%) | |||||
| 1 Never | 3146 (82.9) | 820 (86.3) | 803 (84.6) | 733 (77.2) | 790 (83.2) |
| 2 | 194 (5.1) | 43 (4.5) | 52 (5.5) | 57 (6.0) | 42 (4.4) |
| 3 | 58 (1.5) | 13 (1.4) | 15 (1.6) | 17 (1.8) | 13 (1.4) |
| 4 Always | 25 (0.7) | 9 (0.9) | 5 (0.5) | 5 (0.5) | 6 (0.6) |
| NA | 374 (9.8) | 65 (6.8) | 74 (7.8) | 137 (14.4) | 98 (10.3) |
| Bullying items | |||||
| Cyberbullying (%) | |||||
| No | 3038 (80.0) | 821 (86.4) | 748 (78.8) | 701 (73.9) | 768 (80.9) |
| Yes | 299 (7.9) | 40 (4.2) | 88 (9.3) | 93 (9.8) | 78 (8.2) |
| NA | 460 (12.1) | 89 (9.4) | 113 (11.9) | 155 (16.3) | 103 (10.9) |
| Bullying classmates (%) | |||||
| No | 1225 (32.3) | 749 (78.8) | 460 (48.5) | 16 (1.7) | 0 (0.0) |
| Yes | 144 (3.8) | 77 (8.1) | 65 (6.8) | 2 (0.2) | 0 (0.0) |
| NA | 2428 (63.9) | 124 (13.1) | 424 (44.7) | 931 (98.1) | 949 (100.0) |
| Threatening others (%) | |||||
| No | 3339 (87.9) | 839 (88.3) | 847 (89.3) | 805 (84.8) | 848 (89.4) |
| Yes | 35 (0.9) | 16 (1.7) | 14 (1.5) | 2 (0.2) | 3 (0.3) |
| NA | 423 (11.1) | 95 (10.0) | 88 (9.3) | 142 (15.0) | 98 (10.3) |
Note: Individual twin.