Table 1. Sample Characteristics.
| Controls (n=18) | ADHD (n=15) | Test statistic (d.f.) | p | |
|---|---|---|---|---|
| Age (SD) | 25.44 (6.77) | 29.87 (8.65) | U(33)=99.50 | 0.20 |
| Estimated full scale IQ (SD) | 116.83 (16.07) | 107.13 (12.78) | U(27)=51.00 | 0.06 |
| Abbreviated WAIS-IIIa | 124.25 (14.70) | 109.44 (15.16) | U(17)=17.00 | 0.07 |
| Abbreviated WAIS-Rb | 102.00 (1.63) | 103.67 (8.12) | U(10)=11.50 | 0.91 |
| Years of education (SD) | 17.11 (3.32) | 16.20 (3.63) | t(31)=0.75 | 0.46 |
| CAARS t-scores (SD) | ||||
| Inattention/memory problems | 43.77 (7.41) | 74.00 (10.49) | t(26)=8.67 | <0.0005* |
| Hyperactivity/restlessness | 43.76 (6.08) | 62.27 (12.93) | t(21.79)=4.82 | <0.0005* |
| Impulsivity/emotional lability | 42.92 (9.42) | 58.53 (11.28) | t(26)=3.94 | 0.001* |
| Problems with self-concept | 43.08 (5.89) | 63.07 (7.64) | t(26)=7.66 | <0.0005* |
| DSM-IV inattention | 48.73 (12.49) | 84.4 (8.73) | t(26)=8.85 | <0.0005* |
| DSM-IV hyperactivity | 44.69 (8.54) | 68.13 (14.48) | t(26)=5.11 | <0.0005* |
| DSM-IV total | 46.69 (11.64) | 81.47 (10.30) | t(26)=8.39 | <0.0005* |
| ADHD index | 42.00 (8.45) | 66.86 (8.74) | t(26)=7.63 | <0.0005* |
| BDI at intake (SD) | 1.53 (2.00) | 6.04 (3.86) | U(31)=23.50 | <0.0005* |
| Recreational drug use history | ||||
| Stimulants: no. of lifetime uses (SD) | 0.06 (0.24) | 0.36 (0.74) | U(32)=105.00 | 0.17 |
| Marijuana: no. of lifetime uses (SD) | 18.00 (33.08) | 49.27 (90.07) | U(32)=119.50 | 0.22 |
| Nicotine: no. of lifetime uses (SD) | 1359.06 (3677.02) | 1614.13 (5171.99) | U(33)=128.00 | 0.81 |
| No. of smokers | 1 | 1 | ||
Group differences: *p⩽0.05.
a
Wechsler Adult Intelligence Scale–Revised (WAIS-R) (n=9) (Reynolds et al, 1983).
b
Wechsler Adult Intelligence Scale–III (WAIS-III) (n=9) (Pilgrim et al, 1999).