title: Obsessive-compulsive disorder: boundary issues.
abstract: The boundaries between obsessive-compulsive disorder (OCD) and other neuropsychiatric disorders remain unresolved and may well differ from one disorder to another. Endophenotypes are heritable, quantitative traits hypothesized to more closely represent genetic risk for complex polygenic mental disorders than overt symptoms and behaviors. They may have a role in identifying how closely these disorders are associated with another and with other mental disorders with which they share major comorbidity. This review maps the nosological relationships of OCD to other neuropsychiatric disorders, using OCD as the prototype disorder and endophenotype markers, such as cognitive, imaging, and molecular data as well as results from demographic, comorbidity, family, and treatment studies. Despite high comorbidity rates, emerging evidence suggests substantial endophenotypic differences between OCD and anxiety disorders, depression, schizophrenia, and addictions, though comparative data is lacking and the picture is far from clear. On the other hand, strong relationships between OCD, Tourette syndrome, body dysmorphic disorder, hypochondriasis, grooming disorders, obsessive-compulsive personality disorder, and pediatric autoimmune neuropsychiatric disorders associated with streptococcus are likely. Studies designed to delineate the cause, consequences, and common factors are a challenging but essential goal for future research in this area.
authors.affiliation: Postgraduate School of Medicine, University of Hertfordshire, Gueen Elizabeth II Hospital, Welwyn Garden City, UK. kim.fox@hpt.nhs.uk
authors.forename: Naomi A
authors.initials: NA
authors.lastname: Fineberg
authors.forename: Sanjaya
authors.initials: S
authors.lastname: Saxena
authors.forename: Joseph
authors.initials: J
authors.lastname: Zohar
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Craig
mesh_terms: D001008:Anxiety Disorders / Q000453:epidemiology; D001921:Brain / Q000000981:diagnostic imaging; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006801:Humans; D009771:Obsessive-Compulsive Disorder / Q000145:classification* / Q000188:drug therapy / Q000453:epidemiology; D010641:Phenotype; D049268:Positron-Emission Tomography; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use
chemical_list: D017367:Selective Serotonin Reuptake Inhibitors