Effective medications that can reduce the severity of PD, however, are not always free of side-effects. Sometimes, serious adverse effects of hallucinations, delusions and paranoia can occur. The drug clozapine, not yet approved for PD, has been shown in clinical trials to ease such side-effects without aggravating Parkinsonian motor symptoms. In addition, in some people, PD medications known as dopamine agonists have been found to cause impulsive behaviors — most commonly pathologic gambling, compulsive eating and shopping — and hypersexuality. Reducing or stopping the medication eliminates these problems.