title: The classification of Obsessive-Compulsive and Related Disorders in the ICD-11.
abstract: BACKGROUND
  To present the rationale for the new Obsessive-Compulsive and Related Disorders (OCRD) grouping in the Mental and Behavioural Disorders chapter of the Eleventh Revision of the World Health Organization's International Classification of Diseases and Related Health Problems (ICD-11), including the conceptualization and essential features of disorders in this grouping.
  
  
  METHODS
  Review of the recommendations of the ICD-11 Working Group on the Classification for OCRD. These sought to maximize clinical utility, global applicability, and scientific validity.
  
  
  RESULTS
  The rationale for the grouping is based on common clinical features of included disorders including repetitive unwanted thoughts and associated behaviours, and is supported by emerging evidence from imaging, neurochemical, and genetic studies. The proposed grouping includes obsessive-compulsive disorder, body dysmorphic disorder, hypochondriasis, olfactory reference disorder, and hoarding disorder. Body-focused repetitive behaviour disorders, including trichotillomania and excoriation disorder are also included. Tourette disorder, a neurological disorder in ICD-11, and personality disorder with anankastic features, a personality disorder in ICD-11, are recommended for cross-referencing.
  
  
  CONCLUSIONS
  Alternative nosological conceptualizations have been described in the literature and have some merit and empirical basis. Further work is needed to determine whether the proposed ICD-11 OCRD grouping and diagnostic guidelines are mostly likely to achieve the goals of maximizing clinical utility and global applicability.
  
  
  CONCLUSIONS
  It is anticipated that creation of an OCRD grouping will contribute to accurate identification and appropriate treatment of affected patients as well as research efforts aimed at improving our understanding of the prevalence, assessment, and management of its constituent disorders.
authors.affiliation: Department of Psychiatry and MRC Unit on Anxiety and Stress Disorders, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa. Electronic address: dan.stein@uct.ac.za.
authors.forename: D J
authors.initials: DJ
authors.lastname: Stein
authors.affiliation: School of Psychology, University of Ottawa, Ottawa, Canada.
authors.forename: C S
authors.initials: CS
authors.lastname: Kogan
authors.affiliation: Department of Psychiatry, School of Medicine, Firat (Euphrates) University, Elazig, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Atmaca
authors.affiliation: Highly Specialized Obsessive Compulsive and Related Disorders Service, Hertfordshire Partnership University NHS Foundation Trust, Rosanne House, Welwyn Garden City, UK; Postgraduate Medical School, University of Hertfordshire, Hatfield, UK; University of Cambridge, School of Clinical Medicine, Cambridge, UK.
authors.forename: N A
authors.initials: NA
authors.lastname: Fineberg
authors.affiliation: Institute of Psychiatry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil; "D'Or' Institute for Research and Education, Rio de Janeiro, RJ, Brazil; School of Psychological Sciences, Monash University, Melbourne, Australia.
authors.forename: L F
authors.initials: LF
authors.lastname: Fontenelle
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Grant
authors.affiliation: Department of Neuropsychiatry, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya Hyogo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Matsunaga
authors.affiliation: National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.
authors.forename: Y C J
authors.initials: YCJ
authors.lastname: Reddy
authors.affiliation: College of Physicians and Surgeons, Columbia University Medical College, New York, NY, USA; Anxiety Disorders Clinic and the Center for OCD and Related Disorders, New York State Psychiatric Institute, New York, NY, USA.
authors.forename: H B
authors.initials: HB
authors.lastname: Simpson
authors.affiliation: Centre for Child and Adolescent Psychiatry, Aarhus University Hospital, Risskov, Aarhus, Denmark.
authors.forename: P H
authors.initials: PH
authors.lastname: Thomsen
authors.affiliation: Department of Psychiatry, VU University Medical Center (VUmc), Amsterdam, The Netherlands; Department of Anatomy & Neurosciences, VUmc, Amsterdam, The Netherlands.
authors.forename: O A
authors.initials: OA
authors.lastname: van den Heuvel
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Center for Anxiety Disorders and Trauma, South London and Maudsley NHS Foundation Trust, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Veale
authors.affiliation: Psychology Department, Texas A&M University, College Station, TX, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Woods
authors.affiliation: Department of Psychology, National Autonomous University of Mexico (UNAM), Mexico, DF, Mexico; National Institute of Psychiatry "Ramón de la Fuente Muñiz", Mexico, DF, Mexico; Department of Mental Health and Substance Abuse, World Health Organization, Geneva, Switzerland.
authors.forename: G M
authors.initials: GM
authors.lastname: Reed
mesh_terms: D057215:Body Dysmorphic Disorders / Q000145:classification; D003193:Compulsive Personality Disorder / Q000145:classification* / Q000175:diagnosis*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D000067836:Hoarding Disorder / Q000145:classification; D006801:Humans; D006998:Hypochondriasis / Q000145:classification; D009771:Obsessive-Compulsive Disorder / Q000145:classification* / Q000175:diagnosis*; D005879:Tourette Syndrome / Q000145:classification; D014256:Trichotillomania / Q000145:classification; D055815:Young Adult
keywords: Classification; Global public health; ICD-10; ICD-11; Obsessive–Compulsive Disorder