Course of irritability, depression and apathy in Huntington's disease in relation to motor symptoms during a two-year follow-up period.

BACKGROUND: Irritability, depression and apathy are frequently reported neuropsychiatric symptoms of Huntington's disease (HD).

OBJECTIVE: This study investigated the course of irritability, depression and apathy in HD during a 2-year follow-up period.

METHODS: In 121 HD mutation carriers the presence of irritability, depression and apathy was measured with the Problem Behaviours Assessment (PBA). Multivariate linear regression analysis was performed to assess their relationships with the change of the motor score of the Unified Huntington's Disease Rating Scale (UHDRS-m) in premotor symptomatic (n = 46) and motor symptomatic mutation carriers (n = 75).

RESULTS: The median depression score of all participants decreased (p = 0.002), whereas irritability and apathy scores did not change significantly. In the total group of mutation carriers, a borderline significant association was found between an increase in motor symptoms and an increase in irritability (p = 0.05), and a trend was found for the association between an increase in motor symptoms and a decrease in depression (p = 0.06). Only in the at baseline premotor symptomatic mutation carriers was an increase in motor symptoms significantly related to an increase in irritability (p = 0.02).

CONCLUSION: An increase in motor symptoms in the at baseline premotor symptomatic mutation carriers is related to an increase in irritability, which may be an early and sensitive marker for disease progression.