People with bipolar disorder have a higher risk of developing Parkinson’s disease, according to a new study. Moreover, among those with a more severe form of the disorder, the risk is even higher.
Previous studies have found a link between depression and Parkinson’s disease, but few have tested whether those with bipolar disorder are also at increased risk for developing the disease.
Recently, researchers from the Taipei Veterans General Hospital in Taiwan have decided to examine whether there is a possible link between the two diseases. The findings were published in the Journal of Neurology.
The risk of Parkinson’s is seven times higher.
In this study, the researchers examined the medical data of 56,340 people with bipolar disorder, all of whom were diagnosed with the disorder between 2001 and 2009. Their data were compared with the medical records of 225,360 people in Taiwan who were not diagnosed with bipolar or Parkinson’s disease.
The researchers tracked the two groups in 2011. After the analysis, it was found that 0.7% of those with bipolar disorder developed Parkinson’s disease during the study period. In contrast, only 0.1% of subjects in the control group had the disease.
The researchers adjusted their findings and isolated various variables that could affect the likelihood of developing Parkinson’s, including medical history, age, and history of diseases and injuries that affect the brain. Participants diagnosed with bipolar disorder were seven times more likely to develop Parkinson’s than those who did not.
The researchers also noticed a further difference between the two groups. Those with bipolar disorder tended to have Parkinson’s at a younger age which is 64 on average, than those who had the disorder. Among the control group, the mean age for the disease was 73.
The study also found that the severity of bipolar disorder also affected the risk level. Patients who were hospitalized many times due to the disorder were most likely to develop Parkinson’s later in life. For example, those who arrived at the hospital 1-2 times a year were four times more likely to develop Parkinson’s than those with bipolar disorder and were hospitalized less frequently.
For patients who were hospitalized more than twice a year, the results were the most dramatic. The subjects in this group had a 6-fold increased risk of developing Parkinson’s than those admitted less than once a year due to bipolar disorder.
Limitations of the study.
It is important to note that there are a number of limitations in this study. First, the researchers included only patients who referred to a medical agent and were diagnosed with bipolar disorder. In fact, there are many people who suffer from the disorder and did not seek medical help at all.
Second, the data used by the researchers did not include any information about a family history of Parkinson’s. In addition, no information was given about environmental factors that could affect the likelihood of developing the disease.
Additionally, further research is needed to substantiate the claim that bipolar and Parkinson’s disease share common processes that will explain the relationship between the two states. These processes may be genetic changes, inflammatory processes, or problems related to the transmission of messages between brain cells. Identifying the cause of the association between bipolar disorder and Parkinson’s disease may help develop therapies that may help treat both conditions.