Antidepressants and Parkinson's Disease
What antidepressant medication is preferred for patients with Parkinson's disease (PD)? Would that recommendation change depending on which dopamine agonist the patient receives?

Ljubisha Vishuski, MD

Clinical trials assessing effectiveness and safety of the different antidepressant drugs in PD patients are minimal. Therefore, it is not easy to give a recommendation on precisely how to treat depression associated with PD on the basis of scientific data. To date, only 3 controlled studies with a short follow-up period have been performed: nortriptyline vs placebo (significant benefit with nortriptyline); fluvoxamine vs amitriptyline (similar improvement in both groups); and citalopram vs placebo (no significant differences between the 2 groups).

The minimal information available on this topic contrasts with the fact that depression is the most common psychiatric symptom in PD -- it is present in about 50% of patients. Recognition and treatment of depression is important because depression has a negative impact on quality of life.

Tricyclic antidepressants or selective serotonin reuptake inhibitors (SSRIs) are widely used in clinical practice. SSRIs are associated with fewer antimuscarinic side effects, less sedation, and less cardiac arrhythmia than are the tricyclic compounds. Clinical consensus among many physicians is that sertraline or paroxetine might be first-line agents in this drug class. A few reports have suggested that SSRIs may aggravate parkinsonian symptoms. However, trials assessing the effect of SSRIs on motor performance in PD patients failed to find a significant worsening of motor symptoms.

It has been suggested that the association of SSRIs with the monoamine oxidase B (MAO B) inhibitor selegiline should be avoided because of the risk of developing a serotonin syndrome. However, if this side effect occurs at all, it must be exceedingly uncommon.

Among tricyclics, nortriptyline causes fewer anticholinergic effects than do other drugs in the class; therefore, this drug could be considered in patients who do not respond to SSRIs. Finally, recent studies suggest that pramipexole, a dopamine agonist, has antidepressant effects in PD patients; however, larger studies are required to make a conclusion regarding the drug's efficacy.