title: A twin study of DSM-III-R anxiety disorders.
abstract: The prevalence of anxiety disorders was studied in a sample of 20 monozygotic (MZ) and 29 dizygotic (DZ) co-twins of anxiety disorder probands. A comparison group of co-twins of 12 MZ and 20 DZ twin probands with other non-psychotic mental disorders was also studied. All subjects were personally interviewed with the Structured Clinical Interview for DSM-III-R Axis I (SCID-I). Panic disorder was significantly more prevalent in co-twins of panic probands. Generalized anxiety disorder (GAD) was more prevalent in co-twins of GAD probands with a history of mood disorder (NS). Post-traumatic stress disorder was significantly more prevalent in co-twins of anxiety probands and was more prevalent in MZ than in DZ co-twins. The prevalences of social and simple phobia were equal in co-twins of anxiety and comparison probands. For both panic disorder and generalized anxiety disorder the MZ:DZ concordance ratio was more than 2:1. The results support the hypothesis of a genetic contribution in the etiology of panic disorder, generalized anxiety disorder and post-traumatic stress disorder. The hypothesis that simple and social phobia are mainly caused by environmental experiences was also supported.
authors.affiliation: Department of Psychology, University of Oslo, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Skre
authors.forename: S
authors.initials: S
authors.lastname: Onstad
authors.forename: S
authors.initials: S
authors.lastname: Torgersen
authors.forename: S
authors.initials: S
authors.lastname: Lygren
authors.forename: E
authors.initials: E
authors.lastname: Kringlen
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D004200:Diseases in Twins / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D009626:Terminology as Topic; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics