Pathologic gambling in Parkinson's disease: A behavioral manifestation of pharmacologic treatment?

We describe 12 patients with Parkinson's disease and pathologic gambling. T his association has apparently never been reported. The patients were selec ted from a Parkinson's disease unit of 250 patients. They met Diagnostic an d Statistical Manual of Mental Disorders, 4th edition, criteria for patholo gic gambling. All patients underwent a neurologic, psychiatric, and psychol ogic examination, specifically noting the presence or absence of psychopath ology in the spectrum of impulse control disorder and the nature of the gam bling. Ten patients started gambling after the onset of Parkinson's disease and treatment with levodopa. The pathologic behavior was exclusively prese nt or was markedly increased in "on" periods in 11 patients. All patients h ad motor fluctuations at the time of the study. Slot machines were the pref erred source of gambling for 10 patients, similar to the Spanish gambling p opulation. That the gambling behavior appears more often in the "on" period s of motor fluctuations and that it begins after the onset of Parkinson's d isease in most patients and worsens with levodopa therapy suggest that it c ould be related to the dopaminergic tone in patients with Parkinson's disea se and motor fluctuations (that is, it could represent a behavioral manifes tation of pharmacologic treatment).