A new study coming from the Umeå University, Sweden suggests that there is a direct link between depression and developing Parkinson’s disease at later stages in life.
The results of the study, led by Dr. Peter Nordström were published on Wednesday in Neurology, the journal of the American Academy of Neurology.
The findings are clear. Not all people who were diagnosed with depression present the risk of developing Parkinson’s disease, yet in severe cases of depression, the danger is almost imminent.
The medical investigation pooled all Swedish citizens in the group age of 50 and above since December 31st, 2005. A special category developed, containing 140,688 subjects who had been previously diagnosed with depression between 1987 and 2012. For each of these, three control subjects were assigned. The total number of people in the control group was 421,718 participants and they presented the same age and sex as the person they were assigned to.
Over the 26 year-span included in the study, 1,485 patients who had been diagnosed with depression developed Parkinson’s disease as well.
Overall, 1 percent of people previously diagnosed for depression developed the disease, while 0.4 of the other group developed Parkinson. The diagnosis for Parkinson usually came 4.5 years after the study began. The possibility of it developing after the threshold decreased considerably.
“We saw this link between depression and Parkinson’s disease over a time span of more than 2 decades, so depression may be a very early symptom of Parkinson’s disease or a risk factor for the disease,” says study co-author.
Parkinson is not a common disease, the researchers noted. Even with people who suffer or suffered from depression, the incidence is quite low. Only that were the incidence does occur, people who have depression are 3.2 times more likely to be diagnosed with Parkinson’s as well.
Furthermore, with the increase of depression severity, the chances of developing Parkinson’s increase. This resulted from the fact that people who were hospitalized for depression five times or above presented a higher incidence of Parkinson’s symptoms than those who had been hospitalized once or never.
In the United States, according to the Parkinson’s Disease Foundation, there are approximately 1 million people suffering from it. It manifests as a loss of brain cells which are responsible for producing chemical dopamine. This results in tremors, muscle rigidity and imbalance.
For practitioners, the findings of the study are welcome. At the same time they confirm what many have until now only suspected. This new study underpins previous knowledge that linked psychiatric and neurological diagnoses, yet nothing so comprehensive has been done so far.
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