Thursday, August 21, 2014

Parkinson's Study Shows How Dopamine Replacement Influences Psychiatric Symptoms

Dopamine replacement is a vital part of Parkinson’s disease (PD) therapy, but new findings show that dopamine replacement during early-stage PD also can increase some psychiatric symptoms. PD patients who had been on at least one type of dopamine-related medication for at least one year experienced higher rates of impulse control problems and daytime sleepiness than patients not on dopamine therapy. On the positive side, dopamine replacement did reduce fatigue in many patients.

These findings, which were published online August 15 in Neurology, represent the first longitudinal data to come from the Parkinson's Progression Markers Initiative. This ongoing observational study enrolled 423 newly diagnosed, untreated Parkinson's patients and 196 healthy controls and will follow them over five years.

“Only recently have the nonmotor symptoms of Parkinson’s come to the forefront of awareness,” said senior author Daniel Weintraub, M.D., an associate professor of psychiatry and neurology at the University of Pennsylvania Perelman School of Medicine. “This study will further our knowledge by showing how these psychiatric symptoms manifest over time and treatment.”

Despite the increased awareness, another finding of this study was that about two-thirds of PD patients who screened positive for depression at any of their evaluations were not taking an antidepressant, suggesting it is still an undertreated symptom.

“The study has value, since longitudinal studies of neuropsychiatric symptoms are relatively uncommon,” said Lisa Shulman, M.D., the Eugenia Brin Professor in Parkinson’s Disease and Movement Disorders at the University of Maryland School of Medicine. “In terms of the management of Parkinson disease, the study highlights the importance of recognizing and treating common nonmotor symptoms including depression and anxiety.”

Weintraub stressed that the results are still preliminary; at the time of publication, 261 PD patients and 145 healthy controls had been assessed at their 12-month evaluation, while 96 PD patients and 83 healthy controls had reached 24 months.

To read about the correlation between depression and Parkinson’s, see the Psychiatric News article, "Depression May Be Linked to Onset of Parkinson’s."



The content of Psychiatric News does not necessarily reflect the views of APA or the editors. Unless so stated, neither Psychiatric News nor APA guarantees, warrants, or endorses information or advertising in this newspaper. Clinical opinions are not peer reviewed and thus should be independently verified.