A new study shows that antidepressant drugs which only affect serotonin, often used as first choice treatments, may not be best for depression in people with Parkinson's disease.
The new research is published in the December 17, 2008, online issue of Neurology, the medical journal of the American Academy of Neurology. Depression affects up to 50 percent of people with Parkinson's disease.
The study is the first to compare an older antidepressant that targets two receptors in the brain with a newer generation serotonin only-based drug and placebo. It is also the largest placebo-controlled study for Parkinson's disease depression.
In the study, scientists gave 52 people diagnosed with Parkinson's disease and depression either nortriptyline, a tricyclic antidepressant (TCA), paroxetine CR, a selective serotonin reuptake inhibitor (SSRI) or a placebo pill. Tricyclics affect both norepinephrine and serotonin, two different receptors in the brain. The people were tested for improvement of depression symptoms at two, four and eight weeks after starting treatment.
The study found that the people who took nortriptyline were nearly five times more likely to see improvement in depression symptoms when compared with the people who took paroxetine CR.