Table 1.
Descriptive characteristics of the study population
| Variable | With ADHD (N = 80 009) | Without ADHD (N = 2 458 118) |
|---|---|---|
| Age at the end of observational period, mean (SD) years | 22.92 (7.20) | 26.64 (7.93) |
| Female, N (%) | 29 829 (37.28) | 1 209 273 (49.20) |
| Birth order, N (%) | ||
| 1st | 34 066 (42.58) | 1 021 815 (41.57) |
| 2nd | 27 444 (34.30) | 907 711 (36.93) |
| 3rd | 12 069 (15.08) | 377 941 (15.38) |
| ≥ 4th | 6 430 (8.04) | 150 651 (6.13) |
| Maternal age at delivery, N (%) | ||
| <35 years | 71 602 (89.49) | 2 196 557 (89.36) |
| ≥35 years | 8 397 (10.50) | 261 344 (10.63) |
| Missing | 10 (0.01) | 217 (0.01) |
| Paternal age at childbirth, N (%) | ||
| <45 years | 76 922 (96.14) | 2 386 888 (97.10) |
| ≥45 years | 2 306 (2.88) | 57 716 (2.35) |
| Missing | 781 (0.98) | 13514 (0.55) |
| Family education, N (%) | ||
| Elementary & upper secondary (≤12 years) | 50 550 (63.18) | 1 315 723 (53.53) |
| Higher (≥13 years) | 29 384 (36.73) | 1 141 066 (46.42) |
| Missing | 75 (0.09) | 1 329 (0.05) |
| Psychiatric comorbidities, N (%) | ||
| Depression | 20 882 (26.10) | 103 233 (4.20) |
| Anxiety | 23 827 (29.78) | 121 608 (4.95) |
| Substance use disorder only | 16 773 (20.96) | 90 187 (3.67) |
| Bipolar disorder | 5 093 (6.37) | 13 452 (0.55) |
| Obesity, N (%) | 3 748 (4.68) | 44 977 (1.83) |