Dopamine Agonists and their risk to induce psychotic episodes in Parkinson's disease: a case-control study

BACKGROUND Psychosis is rare in untreated patients with Parkinson's disease (PD) but the prevalence rises to 40% during dopaminergic treatment. So far, no systematic comparison of the psychogenic potential of different dopaminergic drugs had been performed. METHODS Eighty PD patients with psychotic episodes were compared to an age-matched control group of PD patients without psychotic episodes (n = 120) in a cross-sectional retrospective study. RESULTS We found a positive correlation between psychotic episodes and dementia, number of concomitant medication, and pergolide intake. Odds ratio calculation confirmed the association with dementia. With respect to dopaminergic treatment, pergolide showed the highest odds ratio, levodopa the lowest. An adjusted logistic regression model confirmed the strong association with psychotic episodes and pergolide and no association with levodopa (adjusted odds ratio 2.01 and 0.11, respectively). CONCLUSION The analysis indicates that dementia and concomitant medication are factors in PD associated with psychotic symptoms. Furthermore, different dopaminergic drugs showed markedly different associations with psychotic symptoms.