Seventy-six percent of patients in this large clinical cohort (n = 91) had improvement in psychosis on pimavanserin, while 22% of patients reported side effects.

Positive response to pimavanserin did not differ based on diagnosis, presence of dementia, delusions, use of deep brain stimulation, or prior antipsychotic failure.

Pimavanserin was successfully used with and without other concomitant antipsychotics. At current follow-up, most patients still taking pimavanserin (n = 50) are on monotherapy for Parkinson’s disease psychosis (66%), while the remainder of patients (34%) are on dual therapy, most commonly with quetiapine.