Future of Treating Parkinson Disease Psychosis, Overcoming Challenges in Clinical Trials: Aaron Ritter, MD

WATCH TIME: 4 minutes

"It’s incredibly difficult to conduct trials for sort of what we label, the neuropsychiatric symptoms that come with dementia. One, because many patients are very sick at the time they’re experiencing these symptoms, and there’s challenges around obtaining consent."

According to the Parkinson’s Foundation, between 20% to 40% of patients with Parkinson disease (PD) report the experience of hallucinations or delusions. When followed as the disease progresses over the years, this number increases. Medication, dementia, and delirium are the 3 main contributors to the development of psychosis in PD; however, determining the cause of PD psychosis can be difficult, as these conditions can overlap and produce similar symptoms.

Pimavanserin (Nuplazid; Acadia Pharmaceuticals), an atypical antipsychotic, is the first and only FDA-approved medication for PD psychosis. In the phase 3 trial that paved the way for FDA approval, patients receiving pimavanserin demonstrated significant improvement in the frequency and/or severity of hallucinations and/or delusions without worsening motor function compared with patients on placebo. Aside from pimavanserin, drug development for PD psychosis has been a challenge, with few therapies that have shown clinically meaningful benefit thus far.

Recently, Aaron Ritter, MD, director of the Memory & Cognitive Disorders Clinic at Hoag Neuroscience Institute, sat down for an interview to discuss the challenges with testing agents for PD psychosis. Specifically, he stressed the condition these patients are in, inconsistencies with the standard assessments used, and fluctuation in neuropsychiatric comorbidities. In contrast, he also talked about the future of treating PD psychosis, the potential for combination approaches, and the need to continue research on the pathogenesis of PD.