Table 5.
Characteristics of groups with and without DSM-IV ADHD subtypes based on research criteria
| Comparison (N = 311) M (SD) |
ADHD-C (N=135) M (SD) |
ADHD-I (N = 235) M (SD) |
ADHD-H (N = 40) M (SD) |
F | |
|---|---|---|---|---|---|
| Descriptive characteristics | |||||
| Age | 11.2 (2.9) | 10.9 (2.5) | 11.3 (2.7) | 10.6 (2.4) | 2.8 |
| Parental education (years) | 15.3 (2.1)a | 14.4 (2.3)b | 14.6 (2.3)b | 14.5 (2.2)b | 8.3** |
| Socioeconomic status | 3.6 (1.1)a | 3.1 (1.2)b | 3.1 (1.2)b | 3.0 (1.3)b | 9.2** |
| Full Scale IQ | 112.9 (12.0)a | 101.8 (13.2)b | 100.3 (12.4)b | 108.1 (12.0)c | 54.0*** |
| DSM-IV ADHD symptoms | |||||
| Inattention | 0.6 (1.2)a | 8.0 (1.4)b | 7.7 (1.1)b | 2.4 (1.7)c | 884.2** |
| Hyperactivity-impulsivity | 0.5 (1.0)a | 7.5 (1.4)b | 2.1 (1.7)c | 7.0 (1.0)b | 575.0** |
| Sluggish Tempo ratings | |||||
| Parent | 0.12 (0.36)a | 0.61 (0.63)b | 0.59 (0.60)b | 0.17 (0.31)a | 73.6** |
| Teacher | 0.14 (0.36)a | 0.68 (0.66)b | 0.89 (0.77)c | 0.15 (0.34)a | 54.1** |
| Or rule | 0.16 (0.39)a | 0.86 (0.67)b | 1.05 (0.75)c | 0.18 (0.47)a | 121.2** |
| Concurrent mental disorders | N (%) | N (%) | N (%) | N (%) | Χ2 |
|
|
|||||
| Internalizing Disorders | |||||
| DICA-IV GAD | 23 (7%)a | 35 (26%)b | 36 (15%)b | 8 (20%)b | 28.5** |
| DICA-IV MDD | 6 (2%)a | 24 (18%)b | 35 (15%)b | 2 (5%)a | 42.0** |
| Externalizing Disorders | |||||
| DICA-IV ODD | 22 (7%)a | 77 (57%)b | 65 (27%)c | 17 (43%)d | 136.1** |
| DICA-IV CD | 9 (3%)a | 44 (31%)b | 50 (22%)c | 8 (20%)c | 74.9** |
| Learning Disorders | |||||
| Reading Disorder | 5 (2%)a | 35 (26%)b | 67 (29%)b | 3 (8%)a | 91.9** |
| Math Disorder | 15 (5%)a | 38 (28%)b | 83 (35%)b | 4 (10%)a | 90.7** |
Note: Means and percentages with no shared subscripts are significantly different (P < .01). DICA-IV = DSM-IV Diagnostic Interview for children and Adolescents. GAD = generalized anxiety disorder, MDD = major depressive disorder, ODD = oppositional defiant disorder, CD = conduct disorder.