Approximately one third of problem gamblers in Finland suffer from pathological gambling. An essential factor affecting the genesis of pathological gambling is a dysfunction of the dopaminergic reward system. It may be associated with the pleasure arising from gambling along with the reward and expectance of reward. In Parkinsons's disease patients receiving dopaminergic medication, pathological gambling and disturbances of impulse control are more common than in the average population. Various psychosocial modes of treatment and medications have been developed for the treatment of pathological gambling, but based on current knowledge, none of them displays particular efficacy.