School of Medicine researchers are seeking volunteers with Parkinson’s disease for two studies. One is investigating the effects of antidepressant drugs on depression and motor function. The second study is assessing the safety and effectiveness of a drug for Parkinson’s patients who also have psychotic symptoms.
In the National Institutes of Health-funded depression study, investigators are evaluating paroxetine (Paxil) and venlafaxine XR (Effexor) for alleviating depression and for their potential effect on motor function in patients with Parkinson’s.
“Depression is very common in patients with Parkinson’s disease,” said Kevin J. Black, M.D., associate professor of psychiatry, of neurology, of neurobiology and of radiology and the study’s principal investigator. “Doctors frequently prescribe a class of drugs called selective serotonin reuptake inhibitors for these patients. But we don’t really know how well these drugs work in this population.”
The study will monitor depression levels in participants who receive one of the drugs for 12 weeks. Investigators also will monitor motor function. Neither the researchers nor the study volunteers will know which drug subjects have received or whether they have been given a placebo until the end of the study.
“There have been concerns that this class of drugs, known as SSRIs, might affect motor function,” Black said.
“They are known to alleviate depression in otherwise healthy people, but because the drugs interact with some of the same brain structures affected by Parkinson’s disease, it is important that we take a closer look at their effects in this population to ensure that in attempting to alleviate depression, we aren’t creating other problems,” Black said.
The second study, supported by Ovation Pharmaceuticals, is testing varying doses of a drug called melperone to treat psychosis in patients with Parkinson’s disease. Currently, there are no drugs approved specifically for the treatment of psychosis in patients with Parkinson’s. Typical antipsychotic drugs often cannot be used because they can exacerbate Parkinsonian symptoms, such as stiffness and tremors.
“Because melperone seems to work through different mechanisms than other antipsychotic drugs, we want to see whether it can alleviate symptoms of psychosis without exacerbating motor problems,” Black said.
Patients in the 10-week study will receive melperone syrup or a placebo in syrup. Neither the investigators nor the participants will know whether an individual receives an active drug or a placebo until the study’s completion. The study will require seven in-person visits during a 10-week period.
Certain health problems may exclude some people from participating. All screening tests, study medications and research-related procedures for these studies are free of charge.