Neuropsychiatry of Huntington's disease.

Psychiatric manifestations are an integral part of Huntington's disease. They may be divided into those syndromes which resemble idiopathic disorders, but for which HD patients may be particularly at risk, those constellations which are peculiar to HD and related conditions, such as the executive dysfunction syndrome, and those symptoms that can truly be regarded as nonspecific, such as delirium. Most of these problems are believed to arise from subcortical neuropathologic changes. Major depression is a common psychiatric diagnosis, but the executive dysfunction syndrome, a difficult-to-define condition characterized by often simultaneous apathy and disinhibition, may be even more widespread. There are no large controlled studies of psychiatric treatments in HD, but case series, anecdotal reports, and clinical experience indicate that many of these syndromes respond readily to treatment. Further study of the neuropsychiatry of HD may help to reveal the underpinnings of psychiatric conditions found in the general population.