Table 1.
Means, Standard Deviations, and Percentages for Participant Characteristics
| Control n = 71 |
ADHD-only n = 26 |
ADHD-CP n = 125 |
||
|---|---|---|---|---|
| Demographics | M (SD) | M (SD) | M (SD) | p |
| Age in years | 8.8(1.9) | 9.6 (1.7) | 9.1 (2.1) | .201 |
| Full Scale IQa | 111 (16) | 103 (13) | 105 (15) | .032* |
| Gender (% Male)b | 76.9% | 76.9% | 85.6% | .440 |
| Raceb | .692 | |||
| Non-Hispanic White | 78.9% | 73.1% | 80.8% | — |
| African American | 15.5% | 19.2% | 11.2% | — |
| Other | 5.6% | 7.7% | 8.0% | — |
| Maternal Educationb | .564 | |||
| High school or less | 22.4% | 32.0% | 22.3% | — |
| Some college or more | 77.6% | 68.0% | 77.7% | — |
| DSM-IV Symptom Countc | ||||
| ADHD | 1.2 (2.1) | 15.8 (2.5) | 16.9 (1.6) | <.001*** |
| ODD | 0.1 (0.4) | 1.7 (1.0) | 6.5 (1.5) | <.001*** |
| CD | 0.0 (0.2) | 0.5 (0.7) | 2.1 (1.7) | <.001*** |
| DBD Rating Scale d | ||||
| Parent | ||||
| ADHD - Inattention | 0.3 (0.3) | 2.4 (0.6) | 2.2 (0.6) | <.001*** |
| ADHD - Hyp/Imp | 0.2 (0.3) | 1.9 (0.7) | 2.0 (0.6) | <.001*** |
| ODD | 0.2 (0.2) | 0.6 (0.3) | 1.5 (0.6) | <.001*** |
| CD | 0.0 (0.1) | 0.1 (0.1) | 0.3 (0.3) | <.001*** |
| Teacher | ||||
| ADHD - Inattention | 0.3 (0.4) | 2.1 (0.6) | 2.0 (0.8) | <.001*** |
| ADHD - Hyp/Imp | 0.3 (0.4) | 1.3 (0.8) | 1.8 (0.7) | <.001*** |
| ODD | 0.1 (0.2) | 0.6 (0.4) | 1.2 (0.8) | <.001*** |
| CD | 0.0 (0.0) | 0.1 (0.3) | 0.5 (0.6) | <.001*** |
Note.
a
IQ scores were estimated from vocabulary and block design subtests of the WISC-III-R (Wechsler, 1991);
b
Gender, race and maternal education are presented as percentages.
c
Total number of DSM-IV symptom criteria met, based on parent and teacher ratings.
d
Disruptive Behavior Disorders Rating Scale (Pelham et al., 1992).
*
p < .05,
**
p < .01,
***
p < .001.