Nimmagadda SR, Agrawal N, Worrall-Davies A, Markova I, Rickards H. Determinants of irritability in Huntington's disease.
Objectives: Irritability is a common and disabling problem associated with Huntington's disease (HD). However, the underlying causes of such irritability remain unclear. This study investigates the association of irritability in HD with possible aetiological factors including dysexecutive syndrome, depression, anxiety (state and trait) and movement disorder.
Methods: Thirty patients with genetically confirmed HD and their carers were recruited from a regional HD neuropsychiatry service. Patients completed two self-reported questionnaires (Irritability, Anxiety and Depression Scale and State Trait Anxiety Inventory). Their carers filled in the Burns Irritability Scale. Patients were also administered the Behavioural Assessment of Dysexecutive Syndrome (BADS), Montgomery and Asberg Depression Rating Scale (MADRS) and the Motor component of the Unified Huntington's Disease Rating Scale (UHDRS).
Results: Both self-rated and carer-rated irritability scales showed significant positive correlation with trait anxiety. The self-rated irritability scales also showed significant positive correlation with state anxiety and depression. No association was observed between irritability and dysexecutive syndrome or motor impairment.
Conclusions: Trait anxiety might serve as a predictor for irritability in HD. Irritability is unrelated to motor or cognitive features of HD indicating that it is an independent neuropsychiatric manifestation of HD.