Table 2.
Performance on neuropsychological tasks of 288 children and adolescents from 141 extended pedigrees clustering ADHD
| ADHD status [mean (SD)]
|
Effect size
|
Difference of means***
|
Heritability
|
|||||
|---|---|---|---|---|---|---|---|---|
| Unaffected | Affected | Difference* | Pooled** | Statistic | P value | h2 | P | |
| Mental control | 5.52 (2.09) | 4.07 (2.49) | 0.292 | 0.633 | −1.890 | 0.0603 | 0.24 | 0.363 |
| WISC similarities | 11.83 (3.07) | 10.85 (2.99) | 0.154 | 0.324 | −1.092 | 0.2764 | 0.18 | 0.125 |
| WISC vocabulary | 9.52 (2.83) | 9.84 (3.15) | 0.05 | 0.108 | −0.512 | 0.6094 | 0.42 | 0.004 |
| WISC verbal IQ | 105.09 (17.12) | 101.77 (17.06) | 0.091 | 0.194 | −1.520 | 0.1302 | 0.47 | 0.002 |
| WISC picture completion | 10.63 (2.26) | 11.18 (2.47) | 0.109 | 0.235 | 0.794 | 0.4279 | 0.29 | 0.037 |
| WISC block design | 10.16 (2.72) | 9.26 (2.82) | 0.153 | 0.326 | 6,811.5 | 0.0014 | 0.45 | 0.002 |
| WISC performance IQ | 103.82 (14.56) | 100.71 (14.89) | 0.099 | 0.211 | −2.405 | 0.0172 | 0.67 | 0.000 |
| WISC FSIQ | 104.99 (14.66) | 101.83 (13.86) | 0.105 | 0.222 | 7,716.5 | 0.0402 | 0.60 | 0.000 |
| A-CVT correct response | 14.91 (1.33) | 13.61 (2.29) | 0.365 | 0.695 | 7,245.5 | 0.0323 | 0.35 | 0.033 |
| A-CVT omissions | 1.09 (1.33) | 2.36 (2.29) | 0.357 | 0.681 | 9,919.5 | 0.0376 | 0.39 | 0.019 |
| A-CVT commissions | 1.28 (2.01) | 1.41 (1.91) | 0.031 | 0.066 | 8,416.5 | 0.8256 | 0.52 | NA |
| A-CVT errors | 2.37 (2.53) | 3.77 (3.05) | 0.276 | 0.498 | 9,996.5 | 0.0278 | NA | NA |
| Memory verbal span | 7.1 (1.89) | 6.53 (1.83) | 0.145 | 0.306 | −0.448 | 0.6549 | 0.18 | 0.144 |
| Memory number of trials | 2.88 (1.86) | 3.29 (1.89) | 0.102 | 0.216 | 8,840.0 | 0.8215 | 0.38 | 0.02 |
| Memory delay recalls | 8.59 (1.45) | 8.61 (1.58) | 0.006 | 0.014 | 9,236.5 | 0.2154 | 0.24 | 0.10 |
| Memory organization index | 0.61 (0.33) | 0.68 (0.33) | 0.094 | 0.2 | 9,492.5 | 0.1596 | 0.16 | 0.188 |
| ROCFT copy time | 193.84 (85.98) | 221.33 (90.68) | 0.146 | 0.311 | 9,175.5 | 0.5481 | 0.48 | 0.001 |
| ROCFT copy | 27.58 (6.75) | 21.92 (8.68) | 0.396 | 0.728 | 7,373.0 | 0.0383 | 0.39 | 0.021 |
| ROCFT memory time | 129.87 (55.74) | 121.43 (54.55) | 0.073 | 0.153 | 8,014.0 | 0.3898 | 0.03 | 0.453 |
| ROCFT memory | 16.83 (7.86) | 12.48 (7.78) | 0.263 | 0.556 | 7,597.5 | 0.1122 | 0.41 | 0.018 |
| Verbal fluency letter F | 6.86 (3.42) | 5.25 (3.02) | 0.242 | 0.501 | 0.086 | 0.9317 | 0.05 | 0.449 |
| Verbal fluency letter A | 7.84 (3.9) | 5.87 (3.05) | 0.348 | 0.563 | 8,248.5 | 0.4410 | 0.003 | 0.490 |
| Verbal fluency letter S | 7.19 (3.46) | 5.78 (3.39) | 0.197 | 0.414 | 8,819.5 | 0.9042 | 0.19 | 0.147 |
| Phonological total verbal fluency | 21.89 (9.61) | 16.95 (8.38) | 0.265 | 0.549 | −0.399 | 0.6906 | 0.18 | 0.148 |
| Phonological verbal fluency mean | 7.33 (3.23) | 5.63 (2.8) | 0.273 | 0.562 | −0.516 | 0.6068 | 0.17 | 0.154 |
| Verbal fluency animals | 15.86 (4.71) | 14.2 (4.92) | 0.162 | 0.345 | 8,999.0 | 0.7445 | 0.38 | 0.012 |
| Verbal fluency fruits | 11.53 (3.62) | 9.9 (3.43) | 0.221 | 0.463 | 0.435 | 0.6640 | 0.11 | 0.258 |
| Semantic total verbal fluency | 27.39 (7.55) | 24.08 (7.42) | 0.209 | 0.442 | 0.635 | 0.5262 | 0.27 | 0.053 |
| Semantic verbal fluency means | 13.72 (3.81) | 12.03 (3.79) | 0.211 | 0.446 | 0.509 | 0.6110 | 0.29 | 0.043 |
| Token test | 33.07 (2.65) | 31.15 (3.66) | 0.325 | 0.604 | 8,568.5 | 0.4886 | 0.11 | 0.438 |
| WCST correct responses | 23.18 (8.88) | 22.13 (12.7) | 0.051 | 0.096 | 8,297.5 | 0.3670 | 0.58 | 0.0003 |
| WCST categories achievement | 2.82 (1.33) | 2.65 (1.45) | 0.056 | 0.12 | 8,584.5 | 0.6458 | 0.33 | 0.037 |
| WCST errors | 25.66 (9.6) | 27.74 (10.41) | 0.097 | 0.207 | 9,261.5 | 0.5599 | 0.30 | 0.073 |
| WCST perseverative errors | 17.44 (8.2) | 18.87 (9.97) | 0.087 | 0.157 | 8,512.5 | 0.5683 | 0.24 | 0.116 |
| WCST non-perseverative errors | 8.21 (4.5) | 8.81 (5.11) | 0.057 | 0.123 | 9,293.0 | 0.5277 | 0.24 | 0.344 |
| WCST percent perseverative errors | 35.66 (15.73) | 38.1 (19.26) | 0.076 | 0.139 | 8,488.5 | 0.5909 | 0.418 | 0.019 |
| WCST number of trial to first category | 12.77 (9.44) | 10.36 (8.71) | 0.128 | 0.265 | 7,155.0 | 0.2532 | 0.098 | 0.311 |
| WCST conceptual responses | 20.51 (8.63) | 18.54 (11.37) | 0.104 | 0.195 | 7,657.0 | 0.1745 | 0.58 | 0.0003 |
| WCST percent of conceptual responses | 42.23 (17.84) | 36.79 (19.01) | 0.139 | 0.296 | −0.871 | 0.3849 | 0.49 | 0.005 |
| WCST failure to maintain set | 0.74 (0.95) | 0.59 (0.82) | 0.079 | 0.163 | 9,114.5 | 0.2984 | NA | NA |
Significance P values of <0.05 are shown in bold
NA parameter cannot be maximized
*
Computed from the value of the t test of the differences between cases and controls
**
Average variance was used in this case
***
Tests for the difference after verification of both normality and homogeneity of variance. If both criteria were met, the t statistic was used; otherwise we used the non-parametric Mann–Whitney U test