Impulse control disorders in Parkinson's disease versus in healthy controls: A different predictive model

Impulse control disorders (ICDs), including compulsive gambling, buying, sexual behaviour and eating, are not only a severe disorder that can affect the general, nonclinical population, but also a serious, increasingly recognized psychiatric complication in Parkinson’s disease (PD). Previous research detected some risk factors for their occurrence in PD patients and in the general population, including impulsivity. However, impulsivity is a multidimensional construct that comprises several aspects, including reflection impulsivity and delay discounting. The present work assessed different facets of impulsivity in both PDpatients and in the healthy controls (HCs) to examine whether they scored differently, and if the occurrence of ICDs in PD patients and in the HCs was predicted by different aspects of impulsivity. The results showed that ICDs in PD patients were predicted by a strong preference for immediate rewards, whereas ICDs in the HCs were predicted by a deficient reflective ability. The present findings may help clinicians in the early identification of PD patients who could develop ICDs by simply assessing their impulsivity in terms of delay discounting. Furthermore, this work contributed to identify another risk factor for ICDs in the non-clinical population.