Declaration of interest
Some studies have found an association between elevated cortisol and subsequent depression, but findings are inconsistent. The cortisol awakening response may be a more stable measure of hypothalamic-pituitary-adrenal function and potentially of stress reactivity.
To investigate whether salivary cortisol, particularly the cortisol awakening response, is associated with subsequent depression in a large population cohort.
Young people (aged 15 years, n = 841) from the Avon Longitudinal Study of Parents and Children (ALSPAC) collected salivary cortisol at four time points for 3 school days. Logistic regression was used to calculate odds ratios for developing depression meeting ICD-10 criteria at 18 years.
We found no evidence for an association between salivary cortisol and subsequent depression. Odds ratios for the cortisol awakening response were 1.24 per standard deviation (95% CI 0.93-1.66, P = 0.14) before and 1.12 (95% CI 0.73-1.72, P = 0.61) after adjustment for confounding factors. There was no evidence that the other cortisol measures, including cortisol at each time point, diurnal drop and area under the curve, were associated with subsequent depression.
Our findings do not support the hypothesis that elevated salivary cortisol increases the short-term risk of subsequent depressive illness. The results suggest that if an association does exist, it is small and unlikely to be of clinical significance.
The UK Medical Research Council (Grant reference: 74882), the Wellcome Trust (Grant reference: 076467) and the University of Bristol provide core support for ALSPAC. This research was supported by NIH grant R01 MH073842 to T.G.O’C., which funded the cortisol collection; Wellcome Trust grant 084268/2/07/Z to G.L., which funded the CIS-R; and the Wellcome Trust Institutional Strategic Support grant 097825.
- Royal College of Psychiatrists
Royal College of Psychiatrists, This paper accords with the Wellcome Trust Open Access policy and is governed by the licence available at http://www.rcpsych.ac.uk/pdf/Wellcome%20Trust%20licence.pdf