A survey of antidepressant drug use in Parkinson's disease

Selective serotonin reuptake inhibitors (SSRIs) are a newer class of antidepressants that may have particular efficacy in Parkinson's disease (PD) given the known serotonergic alterations in this disease. These agents are also thought to have a favorable side-effect profile, particularly in the elderly. Several recent case reports, however, have raised concern that SSRIs may worsen parkinsonian motor function. We surveyed 71 Parkinson Study Group(PSG) investigators using a standardized questionnaire about their usage of antidepressants in PD. Based on estimates provided by 49 investigators (70%)(caring for approximately 23,410 PD patients) who responded, 26% of patients with PD are on pharmacotherapy for depression. These physicians use SSRIs as first line therapy 51% of the time, tricyclic antidepressants 41% of the time and other agents 8% of the time. The most common reasons for selecting SSRIs were their better side-effect profile and perceived greater efficacy. The most common reasons for selecting tricyclic antidepressants were their potential to help with sleep and the physician's experience with this class. Forty-three percent of investigators were concerned that SSRIs might worsen motor function, and 37% of them have had at least one patient in whom they believe this had occurred. Our survey confirms that for treating physicians there remain uncertainties regarding the relative efficacy and tolerability of available antidepressant medications for patients with PD. A controlled clinical trial of antidepressant therapy in PD would be valuable for settling these concerns.