Psychosis is one of the most prevalent non-motor complications in Parkinson's disease (PD). Risk factors for PD psychosis are advancing age, longer disease duration, severe motor symptoms, presence of dementia, sleep disorders, depression and autonomic dysfunction. Treatment is challenging in this setting because antipsychotic medications are known to worse motor symptoms.

To highlight the therapeutic difficulties in PD-related psychosis.

Case description and literature review.

We report a case of a 74-year-old woman with a 9-year history of PD, who presented a complex psychotic disorder consisting in auditory, olfactory and visual (gulliverian and lilliputian) hallucinations, persecutory and sexual delusions. Additionally, the patient presented euthymic mood, without evidence of cognitive impairment or impulse-control disorder. These symptoms began after dopamine agonist therapy (ropinirole 4 mg/day). Other medical conditions that could justify these symptoms were excluded. Initially, ropinirole was removed, but without psychotic remission. Then, she was treated with antipsychotic medication (clozapine 25 mg/day) with full psychotic remission and without significant worsening of motor symptoms.

Clozapine treatment is frequently delayed, mainly for fear of its side effects, particularly agranulocytosis. However, this antipsychotic drug presents many benefits regarding the management of PD-related psychosis, namely few motor effects and even improvement of motor fluctuations.

The authors have not supplied their declaration of competing interest.