Longitudinal evaluation of neuropsychiatric symptoms in Huntington's disease.

A group of 111 patients with Huntington's disease (HD) underwent a minimum of three annual neuropsychiatric assessments, using the Problem Behaviors Assessment for Huntington's Disease (PBA-HD). Longitudinal prevalence of neuropsychiatric symptoms was notably higher than baseline prevalence, suggesting that previous studies may have underestimated the extent of this clinical problem. Moreover, apathy, irritability, and depression were each associated with distinct longitudinal profiles. Apathy progressed over time and across disease stages. Irritability also increased significantly, but only in early stages of HD. Depression did not increase significantly at any stage of disease. The neuropsychiatric syndrome of apathy appears to be intrinsic to the evolution and progression of HD.