title: A high risk twin study of combat-related PTSD comorbidity.
abstract: Combat-related posttraumatic stress disorder (PTSD) is highly comorbid with other mental disorders. However, the nature of the relationship between PTSD and other mental disorders remains unclear. A discordant high-risk twin design was used on data from a sub-sample of the male-male twin pair members of the Vietnam Era Twin Registry to examine whether patterns of comorbidity are consistent with a psychopathological response to combat exposure or reflect familial vulnerability to psychopathology. Mental disorders were assessed via the Mental Health Diagnostic Interview Schedule Version III - Revised. Discordant monozygotic within-pair comparisons revealed that PTSD probands had higher symptom counts and diagnostic prevalences of mood and anxiety disorders than their non-combat exposed co-twins. Monozygotic co-twins of PTSD probands had significantly more mood disorder symptoms than monozygotic co-twins of combat controls or dizygotic co-twins of veterans with PTSD. These findings suggest that a) major depression, generalized anxiety disorder and panic disorder are part of a post-combat response syndrome; b) a shared familial vulnerability also contributes to the association between PTSD and major depression, PTSD and dysthymia, and c) this shared vulnerability is mediated by genetic factors.
authors.affiliation: Women's Health Sciences Division (116B-3), National Center for PTSD, VA Boston Healthcare System, MA 02130, USA. Karestan.Koenen@bmc.org
authors.forename: Karestan C
authors.initials: KC
authors.lastname: Koenen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lyons
authors.forename: Jack
authors.initials: J
authors.lastname: Goldberg
authors.forename: John
authors.initials: J
authors.lastname: Simpson
authors.forename: Wesley M
authors.initials: WM
authors.lastname: Williams
authors.forename: Rosemary
authors.initials: R
authors.lastname: Toomey
authors.forename: Seth A
authors.initials: SA
authors.lastname: Eisen
authors.forename: William R
authors.initials: WR
authors.lastname: True
authors.forename: Marylene
authors.initials: M
authors.lastname: Cloitre
authors.forename: Jessica
authors.initials: J
authors.lastname: Wolfe
authors.forename: Ming T
authors.initials: MT
authors.lastname: Tsuang
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D003130:Combat Disorders / Q000235:genetics* / Q000523:psychology; D004200:Diseases in Twins / Q000235:genetics*; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000150:complications* / Q000235:genetics* / Q000523:psychology; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012042:Registries; D013313:Stress Disorders, Post-Traumatic / Q000150:complications* / Q000235:genetics* / Q000523:psychology; D014728:Veterans / Q000523:psychology*; D014744:Vietnam