The link between Parkinson’s disease and depression is well-established. Many Parkinson’s patients also suffer from clinical depression, and most people diagnosed with the neurodegenerative disease report experiencing mild or moderate depressive symptoms at some point, according to the Parkinson’s Disease Foundation.
For years, scientists have wondered whether depression might actually be an early symptom of the disease, since Parkinson’s affects many parts of the brain that are involved in regulating a person’s mood. Maybe, they thought, Parkinson’s reveals itself first as depression, and only later do motor symptoms commonly associated with the disease, like trembling, emerge.
Now, there’s new evidence to support that theory. A study published Wednesday in the medical journal Neurology finds that people with depression are more likely to develop Parkinson’s disease.
*Image of “brain” via Allan Ajifo/Flickr