Group 1. average annual mean change in score for motor, psychiatric and cognitive measures per group (SD in brackets)
| Non-antidopaminergic medication takers (n=466) | Antidopaminergic medication takers (n=466) | P value | Cohen’s d | |
| UHDRS total motor score | 3.5 (6.8) | 4.1 (7) | 0.215 | 0.09 |
| UHDRS total chorea score | 0.4 (2.7) | −0.1* (2.8) | 0.004 | 0.18 |
| Irritability (PBA) | 0.3 (3.6) | −0.4* (3.1) | 0.003 | 0.21 |
| Depression (PBA) | −0.2 (4.1) | −0.3 (5) | 0.674 | 0.02 |
| Apathy (PBA) | 0.3 (2.7) | 0.5 (3.4) | 0.391 | 0.07 |
| Composite cognitive z-score | 0.8 (3.5) | −0.8† (4.8) | <0.001 | 0.4 |
| TFC score | −0.5 (1.4) | −1* (1.4) | <0.001 | 0.35 |
| UHDRS independence scale | −2.5 (6) | −3.8* (6.8) | 0.004 | 0.2 |
P values are from a univariate analysis of variance (ANOVA) with age and CAG as covariates.
*Indicates a significant difference (p<0.005) when compared with the control non-antidopaminergic medication group.
†Indicates a significant difference (p<0.001) when compared with the control non-antidopaminergic medication group.
PBA, problems behavioural assessment; TFC, total functional capacity; UHDRS, Unified Huntington Disease Rating Scale.