Pathologic gambling in patients with Parkinson's disease

Patients with Parkinson's disease frequently have depression, anxiety, and obsessive-compulsive disorder. We observed two patients who had episodes of pathologic gambling. At the same time, their Parkinson's disease deteriora ted and they initiated self-medication with dopaminergic drugs. In both pat ients, signs were present of an addiction to dopaminergic medication. Patho logic gambling ceased in these patients after a few months. The significanc e of an insufficient dopaminergic reward system in patients with stereotypi cal addictive-like behavior (e.g., pathologic gambling) is discussed in thi s report. The most likely explanation for this newly recognized behavioral disorder in patients with Parkinson's disease is enhanced novelty seeking a s a consequence of overstimulation of mesolimbic dopamine receptors resulti ng from addiction to dopaminergic drugs.