Accuracy of screening instruments for detection of neuropsychiatric syndromes in Parkinson's disease

Parkinson's disease includes neuropsychiatric manifestations, such as depression, anxiety, apathy, psychosis, and impulse control disorders, which often are unreported by patients and caregivers or undetected by doctors. Given their substantial impact on patients and caregivers as well as the existence of effective therapies for some of these disorders, screening for neuropsychiatric symptoms is important. Instruments for screening have a particular methodology for validation, and their performance is expressed in terms of accuracy compared with formal diagnostic criteria. The present study reviews the attributes of the screening instruments applied for detection of the aforementioned major neuropsychiatric symptoms in Parkinson's disease. A quasi-systematic review (including predefined selection criteria, but not evaluating the quality of the reviewed studies) was carried out on the basis of previous systematic reviews (commissioned by the American Academy of Neurology and the Movement Disorder Society) and made current by conducting a literature search (2005-2014). For depression, 11 scales and questionnaires were shown to be valid for Parkinson's disease screening. The recently developed Parkinson Anxiety Scale and the Geriatric Anxiety Inventory demonstrate satisfactory properties as screening instruments for anxiety, and the Lille Apathy Rating Scale for detection of apathy. No scale adequately screens for psychosis, so a specific psychosis instrument should be developed. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (Questionnaire and Rating Scale) are valid for comprehensive screening of impulse control disorders, and the Parkinson's Disease-Sexual Addiction Screening Test for hypersexuality specifically.