Table 2.
Predictor characteristics per group
| Measure | ADHD + ODD | ADHD-only | TD | |||
|---|---|---|---|---|---|---|
| M | SD | M | SD | M | SD | |
| Parental ADHD (%) | 55.3 | – | 68.2 | – | 0 | – |
| Adverse life events | 2.8 | 2.7 | 1.8 | 1.7 | 0.6 | 0.8 |
| Birth weight (gram) | 3427.4 | 642.5 | 3588.4 | 510.9 | 3360.7 | 698.3 |
| Pregnancy duration (weeks) | 39.3 | 2.4 | 39.4 | 2.0 | 39.3 | 2.2 |
| Maternal smoking during pregnancy (%) | 21.6 | – | 27.9 | – | 19.0 | – |
| SES (corrected years of education) | 11.0 | 1.7 | 11.7 | 2.1 | 12.9 | 2.6 |
| Deviant peer affiliation | 27.4 | 5.0 | 29.8 | 5.6 | 31.4 | 3.5 |
| Parental warmth | 1.7 | 0.9 | 1.4 | 0.8 | – | – |
| Parental criticism | 1.9 | 0.9 | 1.7 | 0.9 | – | – |
ADHD attention-deficit hyperactivity deficit, ODD oppositional defiant disorder, TD typically developing, SES socioeconomic status