Source: Neurology  |  Posted 11 years ago

New results indicate that the selective serotonin reuptake inhibitor, paroxetine, can effectively treat depression in patients with Parkinson's disease without aggravating motor symptoms.

While selective serotonin reuptake inhibitors (SSRIs) have been used to manage depression in patients with Parkinson's disease (PD), it has not been definitely determined whether these agents worsen motor symptoms.

The findings are from a study that included 33 non-demented, depressed PD patients. The diagnosis of depression was new in all patients except for six, who were receiving low-dose tricyclics at the time of referral.

In order to minimize the potential rebound effect on motor symptomatology in relation to the anticholinergic properties of tricyclics, patients who had been taking tricyclics were tapered off the drugs at least three months before starting paroxetine.

Paroxetine was added in an unblinded manner, starting with 5 mg a day increased gradually up to 20 mg a day.

Add-on therapy with paroxetine did not modify parkinsonian motor function as determined by Unified Parkinson's Disease Rating Scale scores.

One patient showed marked worsening of tremor after treatment. The authors emphasize that this effect may have occurred as a result of an additive tremor-inducing effect of paroxetine, since tremor is a common side effect of this medication. Notably, the increase in tremor in this patient was fully reversible when paroxetine was withdrawn.

Depression, as evaluated by the Beck Depression Inventory and Hamilton Depression Rating Scale, improved from baseline to the final visit.

The investigators emphasize that their study had an open-label design and further noted that the placebo effect in antidepressant studies can be large. They add that a controlled clinical trial is needed in a larger patient population to establish the efficacy of SSRIs and their effect on motor function in depressed PD patients.