Some dopamine neurons may be more impulsive than others: Why differences in receptors and transporters can affect dopamine function in Parkinson's disease

[Clinical and psychopathological factors associated with impulse control disorders in Parkinson's disease]

INTRODUCTION

Impulse control disorders (ICD) constitute a complication that may arise during the course of Parkinson's disease (PD). Several factors have been linked to the development of these disorders, and their associated severe functional impairment requires specific and multidisciplinary management. The objective of this study was to evaluate the frequency of ICDs and the clinical and psychopathological factors associated with the appearance of these disorders.

METHODS

Cross-sectional, descriptive, and analytical study of a sample of 115 PD patients evaluated to determine the presence of an ICD. Clinical scales were administered to assess disease severity, personality traits, and presence of psychiatric symptoms at the time of evaluation.

RESULTS

Of the 115 patients with PD, 27 (23.48%) displayed some form of ICD; hypersexuality, exhibited by 14 (12.2%), and binge eating, present in 12 (10.1%), were the most common types. Clinical factors associated with ICD were treatment with dopamine agonists (OR: 13.39), earlier age at disease onset (OR: 0.92), and higher score on the UPDRS-I subscale; psychopathological factors with a significant association were trait anxiety (OR: 1.05) and impulsivity (OR: 1.13).

CONCLUSIONS

ICDs are frequent in PD, and treatment with dopamine agonists is the most important risk factor for these disorders. High impulsivity and anxiety levels at time of evaluation, and younger age at disease onset, were also linked to increased risk. However, presence of these personality traits prior to evaluation did not increase risk of ICD.