Medication-related impulse control and repetitive behaviors in Parkinson disease.

A range of behaviors presumed to be related to aberrant or excessive dopaminergic medications are being increasingly recognized in Parkinson disease. These behaviors are linked by their incentive- or reward-based and repetitive natures and include pathological gambling, hypersexuality, compulsive shopping, compulsive eating, hobbyism, and compulsive medication use. Such behaviors can have potentially devastating psychosocial consequences and are often hidden. Whether these behaviors are simply related to dopaminergic medications interacting with an underlying individual vulnerability or whether the primary pathological features of Parkinson disease play a role is not known. We reviewed the literature on these behaviors in Parkinson disease, including definitions, epidemiological and potential pathophysiological features, and management. The study of these behaviors allows not only improved clinical management but also greater insight into a biologically mediated complex behavioral model.