Mean scores on the pre- and the post-test psychometric tests for the group with the Test participant's Age at the Parental Onset of HD (TAPO) ⩽5 years versus TAPO >5 years and statistical significance of the differences between the two groups (one tailed t test)
| Tests | TAPO ⩽5 years (n=16) Mean (SD) | TAPO >5 years (n=53) Mean (SD) | p value |
| Pre-test | |||
| Ego strength | 51.9 (12.7) | 59.8 (9.1) | <0.01 |
| General anxiety | 42.2 (13.1) | 36.0 (7.9) | <0.05 |
| Depression | 9.4 (10.4) | 4.1 (4.0) | <0.05 |
| Post-test | |||
| Ego strength | 55.4 (10.4) | 59.5 (11.4) | 0.10 |
| General anxiety | 37.7 (13.4) | 34.8 (8.1) | 0.21 |
| Depression | 5.3 (7.4) | 3.4 (4.9) | 0.17 |