Examining the link between impulse control disorder and antidepressant use in Parkinson's disease.

INTRODUCTION

Impulse control disorders (ICD) in Parkinson's disease (PD) and hypomanic episodes of bipolar disorder show overlapping symptoms, suggesting a shared neurobiology. To explore this, the following hypotheses are tested: (1) larger changes in affective symptoms from OFF to ON medication states will be associated with ICD, (2) antidepressant exposure will be associated with larger OFF to ON affective symptom changes, and (3) antidepressant exposure will be associated with ICD.

METHODS

200 participants (mean age 65, 61 % male) were evaluated in "off" and "on" dopamine states. Affective symptoms were captured using the Hamilton Anxiety and Depression Rating Scales. Differences in clinical outcomes were compared using two-sample Wilcoxon rank-sum tests and Pearson χ2 tests. We performed multivariable logistic regression to assess the association of antidepressant exposure on ICD.

RESULTS

Participants with an ICD had higher anxiety and depressive scores in "on" and "off" states and larger changes in depressive symptoms from OFF to ON states compared to those without an ICD. Participants on antidepressants had higher anxiety scores in "on" and "off" states, higher depressive scores in the "off" state, and larger changes in anxiety symptoms from OFF to ON states than those not on an antidepressant. Antidepressant use was associated with a higher odds of an ICD (OR 2.3, CI [1.0-4.5], p-value 0.04).

CONCLUSIONS

Affective symptom severity in "on" and "off" dopamine states is associated with ICD. Antidepressant therapy may be associated with ICD. Future prospective studies clarifying temporal associations between antidepressant initiation and ICD emergence are needed.