Impulse control disorders in Parkinson's disease: don't set your mind at rest by self-assessments.

BACKGROUND AND PURPOSE Impulse control disorders (ICDs) and related conditions in Parkinson's disease (PD) patients are frequent, disabling and sometimes devastating neuropsychiatric behaviors. Current knowledge on the prevalence of ICDs in PD is mainly based on assessments with questionnaires or patient interviews. This study was designed to evaluate the reliability of self-assessed ICDs and related conditions in PD by exploring the agreement between self-assessment of ICDs and related conditions in PD patients on the one hand and the estimation of their caregivers on the other hand. METHODS After a short validation study of a novel ICD screening questionnaire, a cross-sectional study in 150 PD patients was performed. All patients filled out the self-assessment version of a screening questionnaire for ICDs, and caregivers completed an adapted version (n = 64). RESULTS When comparing self-assessments of PD patients and ratings by their caregivers, significant differences with regard to the estimated prevalence of hypersexuality (55% vs. 17%), dopamine dysregulation syndrome (31% vs. 3%) and punding (22% vs. 9%) were found. CONCLUSIONS Patients underestimate the presence and severity of some ICDs and related conditions, which shows how important assessments with caregivers are. After all, ICDs are probably much more frequent in PD than previously reported.