Struggling with bipolar disorder is hard enough, but now a new study from Taiwan suggests these patients are seven times more likely to develop Parkinson’s disease.
But U.S. experts cautioned that the absolute risk of developing Parkinson’s — an incurable movement disease — is still very low for those with the mood disorder. Also known as manic-depressive illness, bipolar disorder is a mood disorder marked by swings from elated, energized behavior to feelings of sadness and hopelessness. It affects about 2.6% of American adults, according to the U.S. National Institute of Mental Health.
Parkinson’s is a progressive condition causing tremors, rigid muscles and slowed movement, among other symptoms. By 2030, the Parkinson’s Foundation projects 1.2 million Americans will be living with the disease. For the study, researchers led by Dr. Mu-Hong Chen of Taipei Veterans General Hospital reviewed health records for 56,000 people in Taiwan who were diagnosed with bipolar disorder between 2001 and 2009. They were compared to 225,000 people with no history of bipolar or Parkinson’s. Both groups were tracked until late 2011.
During the study period, 372 people with bipolar disorder — or 0.7% — developed Parkinson’s. This compared to 222 — or 0.1% — of those who didn’t have bipolar disorder.
Those with bipolar who developed Parkinson’s were nine years younger — average age 64 — than others who also developed Parkinson’s, the study found.