Antiparkinsonian treatment for depression in Parkinson's disease: Are selective serotonin reuptake inhibitors recommended?

Depression is a frequent comorbid syndrome in Parkinson’s disease. It is a difficult symptom to manage, as patients continuously receive antiparkinsonian medication and may also have to be treated for the amelioration of the side-effects of antiparkinsonian therapy. The first-line treatment for depression in Parkinson’s disease is the use of selective serotonin reuptake inhibitors(SSRIs). The clinical efficacy of these medications in patients with Parkinson’s disease is questionable. In fact, based on their mechanism of action, which requires at least a functional serotonergic system, it is predicted that SSRIs will have lower efficacy in patients with Parkinson’s disease. Here, we consider the mechanism of action of SSRIs in the context of Parkinson’s disease by investigating the fall in the levels of serotonergic markers and the inhibitory outcomes of antiparkinsonian treatment on serotonergic nerve activity. Because certain classes of antidepressant drugs are widely available, it is necessary to perform translational research to address different strategies used to manage depression in Parkinson’s disease.