Study author Albert C. Yang, MD, PhD, with Taipei Veterans General Hospital in Taipei, Taiwan, said that their study suggests that depression may also be an independent risk factor for Parkinson's disease.
Researchers analyzed the medical records of 4,634 people with depression and 18,544 free of depression over 10 years.
They also looked at the risk of Parkinson's disease after excluding people who were diagnosed with Parkinson's disease within two or five years following their depression diagnosis.
During the 10-year follow-up period, 66 people with depression, or 1.42 percent, and 97 without depression, or 0.52 percent, were diagnosed with Parkinson's disease. People with depression were 3.24 times more likely to develop Parkinson's disease than those without depression.
The study has been published online in journal Neurology.