Table 1.
Clinical and demographic description of sample.
| ADHD vs. control | ADHD polygenic risk score (European-ancestry only) | |||
|---|---|---|---|---|
| ADHD | non-ADHD | ADHD | non-ADHD | |
| N | 391 | 213 | 302 | 170 |
| Age (years) | 9.8 (1.4) | 9.8 (1.4) | 9.9 (1.4) | 9.8 (1.4) |
| % male | 71.6%* | 51.60% | 72.5%* | 54.10% |
| % European ancestry | 77.20% | 79.80% | 100.00% | 100.00% |
| Family income ($K) | 76.2 (40.7)* | 84.1 (39.0) | 80.2 (40.2) | 85.7 (39.4) |
| Estimated full scale IQ | 108.1 (13.7)* | 115.2 (12.5) | 109.2 (13.2)* | 115.3 (12.7) |
| Inattention(T) | 72.7 (12.1)* | 44.5 (7.0) | 73.0 (12.2)* | 44.3 (7.0) |
| Hyperactivity-Imp(T) | 67.8 (14.6)* | 45.4 (7.5) | 68.1 (14.7)* | 45.0 (7.5) |
| Lifetime mood disorder | 7.2%* | 2.8% | 7.6%* | 3.0% |
| Lifetime anxiety disorder | 19.9%* | 8.5% | 19.9%* | 8.3% |
| Lifetime conduct disorder | 1.3% | 0.0% | 1.3% | 0.0% |
| Lifetime ODD | 17.6%* | 0.5% | 19.5%* | 0.0% |
| Ever psychiatric med | 45.0%* | 0.9% | 48.3%* | 0.0% |
Medication history was defined as any lifetime use of psychiatric medication
Inattention is the inattention T score by parent-rated ADHD Rating Scale
Differences between ADHD/control groups were determined by Mann–Whitney U tests for continuous measures and Fisher’s exact tests for categorical measures
ODD oppositional defiance disorder, Hyperactivity-Imp Hyperactivity-impulsivity T score
Significant differences (p < 0.05) are indicated with an *