Table 3.
Analysis of Continuous Traits of Attention-Deficit/Hyperactivity Disorder (ADHD) in Cotwins
| 5% |
|||
|---|---|---|---|
| CATSS | TEDS | Merged Samples | |
| Cotwin of male proband mean | 0.43 (1.18) | 0.62 (0.89) | 0.51 (1.08) |
| Cotwin of female proband mean | 0.69 (1.23) | 0.79 (1.02) | 0.73 (1.15) |
| Cotwin of control mean | −0.03 (0.98) | −0.04 (0.99) | −0.03 (0.99) |
| Omnibus ANOVA | F2,6688 = 46.39, p < .01 | F2,4040 = 51.63, p < .001 | F2,10731 = 95.90, p < .001 |
| Planned contrast | t6688 = −2.10, p = .16, d = 0.05 | t4040 = −1.10, p = .27, d = 0.03 | t10731 = −2.38, p < .05, d = 0.05 |
| 10% |
|||
|---|---|---|---|
| CATSS | TEDS | Merged Samples | |
| Cotwin of male proband mean | 0.38 (1.11) | 0.55 (0.89) | 0.45 (1.04) |
| Cotwin of female proband mean | 0.62 (1.14) | 0.79 (0.87) | 0.69 (0.79) |
| Cotwin of control mean | −0.05 (0.97) | −0.07 (0.99) | −0.06 (0.98) |
| Omnibus ANOVA | F2,6688 = 79.35, p < .01 | F2,4040 = 102.30, p < .001 | F2,10731 = 175.90, p < .001 |
| Planned contrast | t6688 = −2.84, p < .01, d = 0.07 | t4040 = −2.36, p = .08, d = 0.07 | t10731 = −3.73, p < .001, d = 0.07 |
Note: Merged samples are analyses of both Child and Adolescent Twin Study in Sweden (CATSS) and Twins Early Development Study (TEDS), merged into a single dataset. Numbers in parentheses are standard deviations. Omnibus analysis of variance (ANOVA) is a comparison of all 3 conditions (cotwins of male probands, cotwins of female probands, and cotwins of controls); planned contrast is a comparison of cotwins of male probands and cotwins of female probands.