The researchers -- who included Miguel Hernan, MD, DrPH, of the Harvard School of Public Health -- used a medical database of more than 3 million people in the U.K.
The researchers compared data on 1,052 Parkinson's disease patients to more than 6,600 people of similar backgrounds who didn't have Parkinson's disease.
The pattern applied to people taking selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants. Past use of antidepressants wasn't linked to Parkinson's disease, the study shows.
However, "this should not be interpreted as evidence that antidepressants cause Parkinson's disease," Hernan says in an American Academy of Neurology news release.
The study will be presented in Boston on May 1 at the American Academy of Neurology's annual meeting.