Hedonistic homeostatic dysregulation in patients with Parkinson's disease on dopamine replacement therapies

Hedonistic homeostatic dysregulation is a neuropsychological behavioural di sorder associated with substance misuse and addiction. The disorder has bee n recognised as a consequence of dopamine replacement therapy (DRT) in 15 p atients with Parkinson's disease. The syndrome typically develops in male p atients with early onset Parkinson's disease, and can occur with orally and subcutaneously administered DRT. These patients take increasing quantities of their DRT, despite increasingly severe drug induced dyskinesias, and ma y develop a cyclical mood disorder with hypomania or manic psychosis. There is impairment of social and occupational functioning. Tolerance develops t o mood elevating effects of DRT and a negative affective withdrawal state o ccurs if the drugs are withdrawn or doses decreased. The clinical features and guidelines for managing this syndrome are discussed. A set of diagnosti c criteria for further investigating this condition is proposed.