Low morning cortisol associated with depression and anxiety: possible adrenal fatigue

Written by Matthew Hogg

Tuesday, 22 January 2013 13:18

A new study has found an association between low salivary cortisol levels in the morning and a diagnosis of depressive and anxiety disorders. The researchers suggest adrenal fatigue as a possible explanation.

Depression and associated mood disorders have traditionally been associated with hyperactivity of the hypothalamic-pituitary adrenal (HPA) axis and elevated levels of adrenal hormones; cortisol in particular. Dutch scientists noted studies indicating abnormally low levels of cortisol may also lead to depression and decided to investigate the association further.

Specifically the team from the Department of Psychiatry, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, examined whether salivary cortisol indicators predict the 2-year course of depression and anxiety disorders.

Information spanning a period of two years from 837 participants of the Netherlands Study of Depression and Anxiety was used in this analysis. Each participant had a depressive and/or anxiety disorder diagnosis based on standard DSM-IV criteria at the start of the study period.

Initially, seven saliva samples were obtained from each of the participants, including the one-hour cortisol awakening response (CAR), evening cortisol level and a 0.5mg dexamethasone suppression test. At follow-up, DSM-IV based diagnostic interviews and Life Chart Interviews that integrate diagnostic and symptom trajectories over 2 years were given to participants to determine if their depression/anxiety had worsened over that time.

The CAR is important as in most people a significant rise in cortisol is seen in the first hour after awakening in the morning. The increased levels of cortisol help to prepare individuals for expected stress (e.g. morning traffic, a day at work etc) and motivate them and help them cope accordingly. Learn more about the CAR here.

The Dutch researchers discovered that 41.5% of the participants had a worsening of their depressive or anxiety disorder over the two year period studied without a remission lasting longer than 3 months.

Analyses of the data showed that a lower CAR value (i.e. lower morning cortisol level) was associated with an unfavorable illness course to a high degree of statistical significance; so much so that a low CAR value translated to an 83% chance of a participant experiencing a worsening of their depression and/or anxiety.

No associations were found between evening cortisol or cortisol suppression after dexamethasone ingestion and the course of participants' depression or anxiety.

The findings are extremely interesting from a scientific and medical point of view and if confirmed may lead to depressive and anxiety disorders being treated on an individual basis according to a patient's cortisol test results.

The researchers suggest that the low morning cortisol may be the result of a condition known as adrenal fatigue (or adrenal exhaustion) in which chronic stress and other factors (genetic susceptibility, toxic exposure, nutritional status) eventually leads to dysfunction of the HPA-axis and suboptimal output of cortisol and other adrenal hormones. Learn more about this condition here.

Reference: Vreeburg SA Hoogendijk WJ Derijk RH van Dyck R Smit JH Zitman FG Penninx BW (2013) Salivary cortisol levels and the 2-year course of depressive and anxiety disorders Psychoneuroendocrinology doi: 10.1016/j.psyneuen.2012.12.017. [Epub ahead of print]