Table 1.
Background, Clinical and Neuropsychological Variables
| Probands With ADHD | Siblings of Probands | Controls | ||||
|---|---|---|---|---|---|---|
| Gender (N; N males; %) | 366 | 325 (88.8) | 359 | 174 (48.5) | 263 | 186 (70.7) |
| N | Mean (SD) | N | Mean (SD) | N | Mean (SD) | |
| Age (years) | 366 | 11.3 (2.6) | 359 | 11.3 (3.0) | 263 | 12.2 (2.5) |
| IQ | 366 | 102.8 (15.7) | 359 | 104.1 (13.4) | 263 | 107.6 (13.7) |
| Conners’ Emotional Lability | ||||||
| Mean1 | 366 | 69.1 (10.6) | 359 | 54.7 (10.5) | 263 | 51.2 (8.2) |
| Parent ratings | 366 | 69.0 (12.9) | 359 | 53.7 (12.3) | 263 | 52.7 (12.0) |
| Teacher ratings | 366 | 69.3 (14.5) | 359 | 55.8 (13.5) | 263 | 49.6 (8.1) |
| Conners’ DSM-IV ADHD | ||||||
| Mean1 | 366 | 75.1 (7.6) | 359 | 55.5 (11.3) | 263 | 51.1 (8.4) |
| Parent ratings | 366 | 78.7 (8.5) | 359 | 54.5 (13.4) | 263 | 52.1 (10.4) |
| Teacher ratings | 366 | 71.5 (10.2) | 359 | 56.5 (12.6) | 263 | 50.2 (9.1) |
| Neuropsychological variables | ||||||
| MRT2, ms | 142 | 764.1 (257.4) | 155 | 718.0 (259.6) | 215 | 592.2 (157.8) |
| RTV2, ms | 142 | 374.6 (232.5) | 155 | 285.8 (216.9) | 215 | 179.2 (129.2) |
| Omission errors, %3 | 288 | 15.3 (11.3) | 291 | 9.1 (8.8) | 234 | 5.6 (5.4) |
| Commission errors, %3 | 288 | 53.3 (18.6) | 291 | 43.5 (19.8) | 234 | 39.4 (18.3) |
| Digit span backwards | 302 | 4.6 (1.8) | 293 | 5.1 (2.0) | 259 | 5.6 (2.0) |
| Choice impulsivity %4 | 332 | 27.5 (32.3) | 317 | 23.8 (29.4) | 237 | 12.6 (22.3) |
| IDIR %5 | 324 | 15.4 (22.2) | 316 | 12.2 (19.5) | 239 | 6.7 (17.6) |
| Delay aversion %6 | 321 | 12.2 (24.4) | 309 | 11.3 (25.0) | 237 | 6.0 (19.5) |
| Go/no-go task | ||||||
| MRT (slow condition; ms) | 293 | 649.2 (235.1) | 297 | 590.0 (185.8) | 235 | 501.0 (123.3) |
| RTV (slow condition; ms) | 293 | 316.2 (223.3) | 297 | 228.5 (170.8) | 235 | 148.0 (105.9) |
| MRT (event rate effect; ms)7 | 288 | −228.7 (195.9) | 291 | −186.5 (140.2) | 234 | −141.4 (92.0) |
| RTV (event rate effect; ms)7 | 288 | −125.2 (200.3) | 291 | −81.5 (141.7) | 234 | −33.2 (100.9) |
| MRT (incentive effect; ms)8 | 153 | −43.0 (151.6) | 155 | −20.5 (115.9) | 218 | 8.4 (73.3) |
| RTV (incentive effect; ms)8 | 153 | −91.7 (183.0) | 155 | −57.5 (145.7) | 218 | −30.2 (103.7) |
| Fast task | ||||||
| MRT (slow condition; ms) | 184 | 931.4 (354.9) | 197 | 894.9 (409.6) | 242 | 683.4 (216.6) |
| RTV (slow condition; ms) | 184 | 461.9 (346.6) | 197 | 369.4 (331.0) | 242 | 209.3 (186.2) |
| MRT (event rate + incentive effect; ms)9 | 179 | −282.5 (233.1) | 194 | −244.8 (209.0) | 241 | −157.8 (118.0) |
| RTV (event rate + incentive effect; ms)9 | 179 | −239.1 (290.3) | 194 | −156.0 (249.3) | 241 | −81.9 (144.5) |
Abbreviations: MRT, mean reaction time; RTV, reaction time variability
Mean score (parent-& teacher-rated subscales)
Mean score (Go/No-go task, slow condition & Fast task, baseline condition)
Mean score of error percentage in the Go/no-go task, slow condition & fast condition;
Percentage of impulsive choices (MIDA task, no-postdelay condition)
Impulsive drive for immediate reward; percentage of impulsive choices (MIDA task, postdelay condition)
Difference of percentages of impulsive choices in no-postdelay condition vs. postdelay condition (MIDA task)
Go/No-go task; fast–slow condition difference
Go/No-go task; incentive – slow condition difference
Fast task; incentive/fast-baseline condition difference