The role of self-awareness and cognitive dysfunction in Parkinson's disease with and without impulse-control disorder

The aim of this study was to investigate the clinical, neuropsychological, and self-awareness correlates of impulse-control disorder (ICD) in a group of 17 Parkinson's disease (PD) subjects with an active ICD and a comparison group of 17 PD subjects without ICD. Self-awareness was assessed with the Beck Cognitive Insight Scale and patient-caregiver discrepancy scores from ratings on the Dysexecutive Questionnaire and the Everyday Memory Questionnaire-Revised. Self-awareness was comparable or increased in those with ICD, versus those without, and measures of neuropsychological functioning did not differ between the two groups. Those with ICD had more motor complications of PD therapy and were more likely to be on an antidepressant than those without ICD, whereas dopaminergic medication profiles were comparable between the two groups. In this group, PD patients with current ICDs were aware of their impulsivity. Although executive dysfunction may contribute to ICD behavior, it is not a necessary component. The awareness of the inability to resist these motivated behaviors may be a source of increased depression.