Research Finds New Potential Depression Treatment for Parkinson's Disease Patients

Scientists from the University of Kentucky College of Medicine recently conducted a study to assess depression treatment for patients with Parkinson's Disease by examining both depressed and non-depressed patients.

Parkinson's disease is a progressive disorder of the nervous system that affects one's movement, and is the fourteenth leading cause of death in the United States. It cannot be cured, but advances in medicine can improve symptoms, including stiffness or slowing of movement, according to the Mayo Clinic.

The scientists' study, published in the journal Psychiatry Research, consisted of 28 patients with Parkinson's disease. 18 were non-depressed and 10 were depressed, and each participated in the same series of tests. First, they were given tests to assess cognitive function and depression symptoms, and then they were re-tested with and without dopamine replacement therapy.

Dopamine replacement therapy is used to manage motor symptoms associated with Parkinson's disease, but many have found it can adversely affect cognition. Past studies, including one conducted by the University of Montreal, found that this therapy compromises the functions of the dorsal striatum, which is responsible for the refinement and control of motor movement as well as decision-making.

The University of Kentucky scientists found that non-depressed Parkinson's patients actually showed improved cognitive function with dopamine replacement therapy, whereas depressed patients' mood and cognitive function actually worsened.

"This was a surprise," said Lee Blonder, Ph.D., the study's principal investigator, in this EurekAlert! news release. "It is the opposite of our original hypothesis that both groups of PD patients would improve in cognitive performance on dopaminergic medications, and that mood in the depressed PD group would also improve."

These findings could be useful moving forward, perhaps as a stepping-stone investigation, especially because 40% of Parkinson's disease patients suffer from depression. The scientists hope that future research will help develop treatments for Parkinson's and depression that do not compromise mental health.