Do Depressive Symptoms Mediate the Relationship Between Hopelessness and Diurnal Cortisol Rhythm?
2015 (English)In: International Journal of Behavioral Medicine, ISSN 1070-5503, E-ISSN 1532-7558, Vol. 22, no 2, 251-257 p.Article in journal (Refereed) Published
BACKGROUND: Research has revealed a well-established relationship of depressive symptoms and hopelessness with a variety of physical illnesses that are associated with a dysfunction of the hypothalamic-pituitary-adrenal-axis.
PURPOSE: The purpose of this study was to test if depressive symptoms mediate the relationship between hopelessness and cortisol, a measure of the hypothalamic-pituitary-adrenal-axis.
METHODS: Hopelessness, depressive symptoms, and diurnal cortisol rhythm were measured in 257 adults (128 women and 129 men; age range, 20-74 years) in this cross-sectional study. To test the hypothesis, two linear regression analyses and asymmetrical confidence intervals around the regression weights were conducted. A second set of analyses was calculated to be able to exclude the possibility of hopelessness as a mediator between depressive symptoms and cortisol.
RESULTS: As predicted, after adjusting for age, gender, awakening time, and medication use, more hopelessness predicted more depressive symptoms and more depressive symptoms predicted a flatter diurnal cortisol rhythm. The 95 % confidence intervals revealed that the indirect relationship between hopelessness and diurnal cortisol rhythm was significant. The analyses with hopelessness as a potential mediator revealed that hopelessness does not mediate the association between depressive symptoms and cortisol.
CONCLUSIONS: While the relationship between hopelessness and cortisol was mediated by depressive symptoms in this cross-sectional study, many other risk factors of depression have not been examined. Thus, future longitudinal studies should examine the relationships between those risk factors of depression and the hypothalamic-pituitary-adrenal-axis.
Place, publisher, year, edition, pages
2015. Vol. 22, no 2, 251-257 p.
Population-based Cross-sectional study Mediation model Hopelessness Depressive symptoms Diurnal cortisol rhythm
Other Medical Sciences not elsewhere specified
IdentifiersURN: urn:nbn:se:liu:diva-115573DOI: 10.1007/s12529-014-9422-6ISI: 000351523600011PubMedID: 25475609OAI: oai:DiVA.org:liu-115573DiVA: diva2:796125