Table 1.
Group Characteristics.
| ADHD + ODD (n = 82) |
ADHD-only (n = 82) |
TD (n = 82) |
|||||
|---|---|---|---|---|---|---|---|
| Measure | M | SD | M | SD | M | SD | Group comparisons |
| Age (years) | 16.3 | 3.1 | 16.3 | 3.0 | 16.1 | 3.3 | ns |
| IQ | 97.5 | 11.2 | 96.9 | 11.0 | 98.3 | 7.3 | ns |
| Gender (% male) | 67 | — | 67 | — | 67 | — | ns |
| SES (average of both parents)a | 11.3 | 2.1 | 11.3 | 2.2 | 12.8 | 2.5 | TD > ADHD, ADHD + ODD** |
| ADHD type (I/HI/C) | 29/4/49 | — | 29/4/49 | — | — | — | ns |
| ADHD total symptomsb | 18.9 | 5.9 | 18.2 | 6.3 | 0.7 | 1.0 | ADHD, ADHD + ODD > TD** |
| Hyperactive symptomsb | 8.5 | 4.0 | 8.0 | 4.0 | 0.3 | 0.6 | ADHD, ADHD + ODD > TD** |
| Inattentive symptomsb | 10.4 | 3.1 | 10.2 | 3.5 | 0.4 | 0.8 | ADHD, ADHD + ODD > TD** |
| ODD symptomsb | 5.2 | 1.1 | 0.4 | 0.9 | 0.0 | 0.0 | ADHD + ODD > ADHD > TD** |
| Global functioning scorec | 5.9 | 1.0 | 6.2 | 1.2 | 8.9 | 0.3 | TD > ADHD > ADHD + ODD*** |
Note. ADHD = attention deficit hyperactivity disorder; ODD = oppositional defiant disorder; TD = typically developing; SES = socioeconomic status; I = predominantly inattentive type; HI = predominantly hyperactive-impulsive type; C = combined type; K-SADS-PL = Kiddie–Schedule for Affective Disorders and Schizophrenia for School-Age Children–Present and Lifetime Version.
a
As measured using the average level of maternal and paternal education (see Buis, 2010)
b
As measured using the combination of K-SADS-PL and Conners’ scales Total, Inattentive, Hyperactive/Impulsive.
c
As measured using the Global Assessment Scale score of K-SADS-PL.
**
p < .01.
***
p < .001.