Depression has long been implicated with a number of unwanted health consequences and a new study now reveals that depression is also an early risk factor for the development of Parkinson's disease, a neurodegenerative disease.
In a new study published journal Neurology on Wednesday, researchers looked at the data of over 560,000 individuals and found that those with depression has nearly three times increased odds of developing Parkinson's compared with other participants in the study.
The researchers likewise found that the more severe depression is, as indicated by the types of treatment received and hospitalizations, the higher the likelihood of developing the disease. If a patient has received numerous hospitalizations due to illnesses related to depression, for instance, the risk factor for developing the condition tends to be much higher.
The researchers said that the results of the study show that depression is a warning sign of Parkinson's, a condition characterized by slurred speech, stiffness, tremors and unusual gait. Actor Robin Williams, who died less than a year ago, was battling with depression and was in the early stages of Parkinson's prior to his death.
"The time-dependent effect, dose-response pattern for recurrent depression, and lack of evidence for coaggregation among siblings all indicate a direct association between depression and subsequent PD," wrote study researcher Peter Nordström, from the Umeå University in Sweden, and colleagues. "Given that the association was significant for a follow-up period of more than 2 decades, depression may be a very early prodromal symptom of PD, or a causal risk factor."
Clinical psychologist Carol Schramke, from Allegheny General Hospital, said that the research highlights the previously known association between psychiatric and neurological disorders.
When a person has depression or symptoms of depression, it is possible that there are also other brain related problems. Besides Parkinson's, depression also possibly involves epilepsy or multiple sclerosis. She added that the likelihood of a second disorder is strong if a person's first bout with depression occurred later in life.
Although there is currently no treatment available for treating or preventing Parkinson's, Schramke said that if preventive measures could be developed one day, the findings of the study can help identify the patients who may be targeted for intervention.
The study, however, does not mean that depression causes Parkinson's but rather those who suffer from depression should be monitored for early signs of the disease.
Photo: Sander van der Wel | Flickr