Impulsive–compulsive behaviours (ICBs) are an increasingly well-recognised adverse-effect of dopaminergic medications used to treat Parkinson's disease. ICBs include pathological gambling, compulsive sexual behaviour, compulsive buying, and binge eating, together with punding and the addiction-like compulsive use of dopamine replacement therapy, or dopamine dysregulation syndrome. The prevalence of ICBs was approximately 14% in a large study undertaken in specialist movement disorder clinics.
Dopamine dysregulation syndrome is more associated with compulsive l-dopa use, whereas other ICBs are more linked with oral dopamine agonist use. Other mechanisms implicated in the development and perpetuation of ICBs in PD include aberrant learning from reward-related situations, including decreased learning from negative feedback, increased measures of impulsivity or sensation seeking, and strong preference for immediate over future rewards.
Treatment options for impulsive–compulsive behaviours include pharmacological, surgical and psychological interventions. The early recognition and prevention of ICBs, coupled with awareness of clinical risk factors for the development of these behaviours is of paramount importance, given the lack of specific treatments for these sometimes debilitating behaviours.