Science Daily. A study published in the scientific journal of the American Academy of Neurology found that depressed people are three times more likely to contract parkinson’s disease than people who are not depressed. It had long been known that parkinson’s patients are more likely to become depressed, but the reverse has also now been found to be true. Both depression and parkinson’s disease involve a lowered level of the neurotransmitter serotonin in the brain.
