Apathy and Impulsivity Co-Occur in Huntington's Disease

Apathy is a debilitating behavioral change in Huntington's disease (HD), but impulsivity in HD has not been well documented, and the co-occurrence of these behaviors in HD has not been investigated.

Our objective was to determine whether apathy and impulsivity co-occur in people with HD and their associations with quality of life.

Carriers of Huntington's gene expansion (premanifest to mild motor manifest disease; n = 42) along with healthy controls (n = 20) completed measures of apathy (Apathy Evaluation Scale and Apathy Motivation Index) and impulsivity (Barratt Impulsiveness Scale-11 and UPPS-P impulsivity scale), along with mood, cognition, clinical, and quality of life measures. Apathy and impulsivity measures were each reduced to a single metric per patient using principal component analysis. Correlations and multiple linear regression models determined associations between apathy and impulsivity and the potential influence of other covariates.

Apathy and impulsivity were significantly correlated (r = 0.6, p < 0.001, 95% CI [0.36, 0.76]) in HD, with this association remaining after controlling for depressive symptoms, motor disease severity, and cognitive function. Furthermore, apathy and depressive symptoms were associated with poorer quality of life.

Apathy and impulsivity co-occur in individuals with premanifest to mild manifest HD and have a significant impact on wellbeing. We add to a growing evidence body that apathy and impulsivity may be intrinsically linked.