Evaluating impulse control disorders in people with Parkinson’s disease: agreement and added value of patient and caregiver reports

Background People with Parkinson’s Disease (PD) treated with dopamine agonists are at increased risk for developing impaired impulse control behavior. It has been suggested that patients tend to underreport problems with impaired impulse control, indicating that caregiver evaluations may be a helpful supplement to clinical assessment. Objective To examine the agreement between evaluations of impaired impulse control provided by people with PD treated with dopamine agonists and by their caregivers. Methods People with PD and their caregivers independently completed the validated Questionnaire for Impulse-Compulsive Disorders in Parkinson’s Disease-Rating Scale (QUIP-RS) and the Impulse Control Disorders and Related Conditions (ICDRC) questionnaire. Patient and caregiver assessment were compared statistically for total scores and subscores on both questionnaires. Results Overall, patient and caregiver assessment on both the QUIP-RS and ICDRC showed no consistent systematic differences. Patients reported a slightly higher total ICDRC score and higher combined subscores for punding and dopamine dysregulation syndrome compared to their caregivers. Further, patient evaluations showed a wider range of responses for hypersexuality (QUIP-RS and ICDRC) and for gambling (ICDRC). Conclusion The assessment of impaired impulse control remains difficult, and our findings indicate that the role of caregiver evaluations is still uncertain.