Depression and Neurological Disease

Which came first: the depression or the disease? Discovering you have a serious chronic illness is depressing enough, but researchers have long suspected that the higher rates of depression in MS may have an organic component. Now a retropective study of patients with Parkinson's lends more weight to the idea that organic brain disease may cause depression in and of itself -- and that indeed depression may be present before there are other symptoms. A diagnosis of depression is associated with a three-fold higher incidence of Parkinson's disease, Dutch investigators report in the May 28th issue of Neurology The study authors suggest that depression may actually represent the first clinical manifestation of Parkinson's disease. They theorize that reduced serotonin activity, as a compensatory mechanism for a reduction in dopamine activity, exists before the onset of motor symptoms in patients with PD. As a result, these patients may have a biologic vulnerability to depression.