The death of award-winning actor Robin Williams earlier this week highlighted the dangers of suffering from both depression and Parkinson's disease.
Although the public was already aware that the actor had been battling with addiction and depression, few knew that Williams was also dealing with the early stages of Parkinson's disease, a condition that affects the nervous system and worsens over time. The ailment is marked by slowed and imprecise movements, muscular rigidity, tremors and other motor problems.
Parkinson's affects the nerve cells of the brain and as these cells break down, they produce insufficient amounts of a chemical in the brain known as dopamine, which is involved in movement. Parkinson's disease may have played a role in worsening Williams's bouts with depression, which many attribute to be one of the factors that led to the actor committing suicide.
The Parkinson's Disease Foundation (PDF) said that of the estimated 10 million people who suffer from Parkinson's disease worldwide, up to 60 percent have symptoms of depression. PDF said that studies suggest that the degenerative disease causes chemical changes in the brain that could result in depression.
The National Institute of Mental Health, or NIMH, also revealed the same. The organization said that Parkinson's and depression together is a dangerous combination because each could make the symptoms of the other disease worse. Those who struggle from both conditions tend to have higher levels of anxiety and may have worse concentration problems compared with people who only suffer from any one of the two ailments.
The NIMH cited the results of a 2008 study which found that individuals with Parkinson's appear to have higher number of "reuptake pumps" for serotonin, a brain chemical associated with mood disorders. Additional activities of these pumps could result in lower levels of serotonin which could explain the cause of depressive symptoms in patients with Parkinson's disease.
As for the effects of depression, Michael Bahntge, a neurologist from the MetroHealth Medical Center in Cleveland, Ohio, said that some drugs used for treating depression could likewise lead to drug-induced parkinsonism, a neurological condition characterized by the same symptoms as Parkinson's disease but is actually caused by another factor.
Benjamin Walter, from the Movement Disorders Center at the University Hospitals Neurological Institute in Cleveland, Ohio said that approximately 50 percent of Parkinson's patients suffer from depression and about 50 percent suffer from anxiety. He said that these are very high numbers when the incidence is compared with that of other diseases.
"A lot of people would expect that depression would be associated with chronic neurodegenerative diseases," Walter said. "In Parkinson's patients, it's a lot more prevalent."
