Psychological features of Huntington's disease and the problem of early detection.

Huntington's disease (HD) is a chronic degenerative neurologic disorder inherited as an autosomal dominant trait. Symptom onset typically occurs at about age 40, and considerable effort has been expended in attempts to diagnose the disorder prior to the childbearing years. We review attempts to use psychological tests in early diagnosis. Specifically, we identify variables that show promise as early markers of the disorder, review evidence that a prodromal phase may exist, analyze the few prospective studies of persons at risk for HD, and consider the logical and methodological problems involved in early detection research.