title: Salivary cortisol in unaffected twins discordant for affective disorder.
abstract: Dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as a biological endophenotype for affective disorders. In the present study the hypothesis that a high genetic liability to affective disorder is associated with higher cortisol levels was tested in a cross-sectional high-risk study. Healthy monozygotic (MZ) and dizygotic (DZ) twins with (High-Risk twins) and without (Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. Awakening and evening salivary cortisol levels were compared between the 190 High- and Low-Risk twins. The 109 High-Risk twins had significantly higher evening cortisol levels than the 81 Low-Risk MZ twins, also after adjustment for age, sex, and the level of subclinical depressive symptoms. No significant difference was found in awakening cortisol levels between High-Risk and Low-Risk twins. In conclusion, a high genetic liability to affective disorder was associated with a higher evening cortisol level, but not with awakening cortisol level. Future prospective family, high-risk and twin studies are needed to decide whether abnormalities in the HPA axis can be identified as an endophenotype of affective disorder.
authors.affiliation: Department of Psychiatry, Rigshospitalet, University Hospital of Copenhagen, Copenhagen, Denmark. Maj.Vinberg@rh.dk
authors.forename: Maj
authors.initials: M
authors.lastname: Vinberg
authors.forename: Bente
authors.initials: B
authors.lastname: Bennike
authors.forename: Kirsten Ohm
authors.initials: KO
authors.lastname: Kyvik
authors.forename: Per Kragh
authors.initials: PK
authors.lastname: Andersen
authors.forename: Lars Vedel
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000097:blood* / Q000235:genetics; D002940:Circadian Rhythm / Q000502:physiology; D003866:Depressive Disorder / Q000097:blood* / Q000235:genetics; D004200:Diseases in Twins / Q000097:blood* / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012307:Risk Factors; D012463:Saliva / Q000737:chemistry
chemical_list: D006854:Hydrocortisone