Table 1.
Sample characteristics
| ADHD (n = 83) | Control (n = 30) | Group comparisons | |
|---|---|---|---|
| Age at assessment in years, M (SD) | 8.34 (1.64) | 8.20 (1.46) | t(111) = .41, p = .683, d = .09 |
| Sex, n (%) boys | 68 (82) | 13 (43) | χ2 = 16.17, p < .001, V = .38 |
| IQ, M (SD) | 100.55 (12.23) | 105.20 (15.21) | t(111) = − 1.67, p = .098, d = .36 |
| TTI symptom severity, M (SD) | |||
| Inattention | 4.53 (1.82) | ||
| Hyperactivity/impulsivity | 4.20 (2.28) | ||
| ODD | 1.10 (1.45) | ||
| CD | .05 (.31) | ||
| Teacher ratings | |||
| SDQ, M (SD) | |||
| Hyperactivity | 8.65 (1.27) | .57 (.82) | t(80.32) = 39.55, p < .001, d = 6.91 |
| Emotional problems | 2.30 (2.32) | 0.87 (1.41) | t(84.95) = 3.97, p < .001, d = .67 |
| Peer problems | 2.31 (2.25) | 0.63 (1.00) | t(106.28) = 5.48, p < .001, d = .84 |
| Prosocial behavior | 6.06 (2.31) | 9.13 (1.20) | t(97.28) = − 9.19, p < .001, d = 1.48 |
| DBDRS, M (SD) | |||
| Inattention | 16.92 (4.84) | ||
| Hyperactivity/impulsivity | 15.60 (6.71) | ||
| ODD | 7.27 (5.73) | 0.53 (.97) | t(93.91) = 10.30, p < .001, d = 1.36 |
| IRS, M (SD) | |||
| Number of domains impairment | 3.90 (1.18) | ||
| SWAN, M (SD) | |||
| Inattention | 13.98 (5.67) | − 12.23 (7.36) | t(50.51) = 16.14, p < .001, d = 4.26 |
| Hyperactivity/impulsivity | 13.90 (7.50) | − 12.27 (7.65) | t(111) = 16.29, p < .001, d = 3.47 |
| Parent ratings | |||
| SDQ, M (SD)a | |||
| Hyperactivity | 6.83 (2.38) | 1.34 (1.84) | t(63.28) = 12.74, p < .001, d = 2.44 |
| Emotional problems | 2.54 (2.40) | 1.76 (1.66) | t(71.15) = 1.91, p = .060, d = .35 |
| Peer problems | 1.70 (1.50) | 0.66 (0.81) | t(90.75) = 4.63, p < .001, d = .77 |
| Prosocial behavior | 8.50 (1.39) | 8.86 (1.68) | t(109) = − 1.14, p = .257, d = .24 |
| DBDRS, M (SD)a | |||
| ODD | 5.78 (4.36) | 2.38 (1.99) | t(102.06) = 5.61 p < .001, d = .88 |
| SWAN, M (SD)b | |||
| Inattention | 6.70 (7.37) | − 9.45 (8.04) | t(104) = 9.81, p < .001, d = 2.14 |
| Hyperactivity/impulsivity | 8.40 (6.99) | − 11.97 (9.05) | t(41.26) = 10.96, p < .001, d = 2.69 |
ADHD attention-deficit/hyperactivity disorder, DBDRS Disruptive Behavior Disorders Rating Scale, IRS impairment rating scale, SDQ Strengths and Difficulties Questionnaire, SWAN strengths and weaknesses of attention-deficit/hyperactivity symptoms and normal behaviors, TTI teacher telephone interview
aTwo parents did not complete this questionnaire (one in the ADHD group, one in the control group)
bSeven parents did not complete this questionnaire (six in the ADHD group, one in the control group)