Regular Research Article Prevalence of Obsessive-Compulsive Symptoms in Elderly Parkinson Disease Patients: A Case-Control Study Maria Rita Lo Monaco, M.D. # , Enrico Di Stasio, M.D. # , Giuseppe Zuccal  a, M.D., Martina Petracca, M.D., Danilo Genovese, M.D., Domenico Fusco, M.D., Maria Caterina Silveri, M.D., Rosa Liperoti, M.D., Diego Ricciardi, F.T., Maria Camilla Cipriani, M.D., Alice Laudisio, M.D., Anna Rita Bentivoglio, M.D., Ph.D. ARTICLE INFO Article history: Received June, 3 2019 Revised August, 22 2019 Accepted August, 22 2019 ABSTRACT Background: The clinical picture of obsessive-compulsive disorder encom- passes a broad range of symptoms that are related to multiple psychological domains, including perception, cognition, emotion, and social relatedness. As obsessive-compulsive symptoms (OCS) frequently have an early onset, there are limited data about OCS in older populations (≥65 years) and, in particular, in elderly subjects with Parkinson disease (PD). Objective: This study aimed to estimate the prevalence of OCS using a self-report measure (Obsessive-Compul- sive Inventory-Revised) and to identify associated sociodemographic and clini- cal factors in a sample of elderly PD patients compared to a comparison group of similarly aged healthy volunteers. Results: The mean age was 74 § 6 years in the PD patients and 73 § 7 years in the comparison group. The mean disease duration was 9.6 § 5.8 years. Among the PD patients, 30.7% reported at least one OCS or a related disorder compared to 21.1% in the comparison group. Hoarding was significantly more common in PD patients than in the compari- son group. Conclusions: Subclinical OCS were present at a high percentage in both PD patients and comparison group. The OCS phenotype in PD may pres- ent differently, as hoarding was more common in PD patients. (Am J Geriatr Psychiatry 2019; &&:&&-&&) Key Words: Obsessive-compulsive disorder hoarding Parkinson disease elderly From the Fondazione Policlinico Universitario Agostino Gemelli, IRCCS (MRLM, EDS, GZ, DF, RL, DR, MCC, ARB), Rome, Italy; Institute of Internal Medicine and Geriatrics, Universit a Cattolica del Sacro Cuore (MRLM, GZ, DF, RL, MCC), Rome, Italy; Institute of Neurology, Uni- versit a Cattolica del Sacro Cuore (MP, DG, ARB), Rome, Italy; Istituto di Biochimica e Biochimica Clinica, Universit a Cattolica del Sacro Cuore (EDS), Rome, Italy; Department of Psychology, Universit a Cattolica del Sacro Cuore (MCS), Milan, Italy; and the Unit of Geriatrics, Depart- ment of Medicine, Campus Bio-Medico di Roma University (AL), Rome, Italy. Send correspondence and reprint requests to Maria Rita Lo Monaco, MD, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, Largo A Gemelli, 8 00168 Rome, Italy. e-mails: rita.lomonaco@gmail.com, mariarita.lomonaco@policlinicogemelli.it © 2019 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jagp.2019.08.022 # These authors contributed equally. Am J Geriatr Psychiatry &&:&&, && 2019 1 ARTICLE IN PRESS Am J of Geriatric Psychiatry &&:&& (2019) &&-&& Available online at www.sciencedirect.com ScienceDirect journal homepage: www.ajgponline.org