Scientists seek causes of Parkinson’s neuropsychiatric symptoms

A new research initiative funded by the U.S. Department of Defense is exploring the causes of neuropsychiatric symptoms in people with Parkinson’s disease. These symptoms, which include depression, anxiety, sleep disturbances, cognitive changes, and sometimes psychosis, affect many Parkinson’s patients and involve both neurological and psychiatric elements. The four-year, $3 million grant supports collaboration between Binghamton University (SUNY), Barrow Neurological Institute in Arizona, and the University of Illinois at Chicago. The team hypothesizes that Parkinson’s disease triggers compensatory brain processes that may contribute to psychiatric issues. They've been working together for over three years. While Parkinson’s is known primarily for motor symptoms due to the loss of dopamine-producing brain cells, non-motor symptoms like psychosis are less understood but affect up to 70% of patients. The researchers are studying how neuroplasticity — the brain’s ability to reorganize itself — might play a role in these psychiatric symptoms. In some cases, serotonin-producing nerve cells begin to produce dopamine when exposed to levodopa, a common Parkinson’s treatment, but this process is uncontrolled and can cause psychiatric side effects. The team is using animal models and postmortem brain samples to investigate these changes. They are also exploring medications that might address these maladaptive brain responses. One existing treatment, Nuplazid, already targets serotonin receptors to reduce psychosis in Parkinson’s patients. The research aims to improve overall symptom management and enhance the quality of life for those with Parkinson’s.