Parkinson's disease (PD) is classified primarily as a movement disorder. Psychiatric complications, however, are common during the progression of the disease. Psychosis is rare in untreated patients with PD, but the prevalence rises to 40% during dopaminergic treatment.

We report the clinical course of a ropinirole induced psychosis in a 57-year-old female with PD.

The patient was treated with different antiparkinsonians (rasagiline, ropinirole and levodopa), and after a dosage increase of ropinirole, psychotic symptoms appeared (auditory hallucinations and paranoid delusion). Antipsychotic treatment started with quetiapine and a gradual dose reduction of antiparkisonians. Nevertheless, psychotic symptoms required a hospital admission.

Rasagiline was suspended at admission, the dose of ropinirole was decreased until withdrawal, and the dose of levodopa was reduced. The dose of quetiapine was increased to control psychotic symptoms.

The pathogenesis of psychosis in PD is poorly understood. It has been related with the presence of dementia and concomitant treatment with dopaminergic agonists (DA). According to the literature, pergolide is associated with a significantly increased risk for the development of psychosis, followed by ropinirole, pramipexole and cabergoline, whereas levodopa has the lowest associated risk. Treatment includes, in the first place, suspending anticholinergics and selegiline, and then, amantadine, DA, and entacapone. Finally, levodopa may also be reduced. These patients frequently require antipsychotic treatment that may worsen extrapyramidal symptoms.

Psychosis should be considered in PD, especially in patients treated with DA. Treatment begins with reducing antiparkinsonians and then adding antipsychotics. Clozapine and quetiapine are a good choice.