Cortisol and α-Amylase Secretion Patterns between and within Depressed and Non-Depressed Individuals

Abstract

ObjectivesAssociations between biological stress markers and depression are inconsistent across studies. We assessed whether inter- and intra-individual variability explain these inconsistencies.MethodsPair-matched depressed and non-depressed participants (N = 30) collected saliva thrice a day for 30 days, resulting in 90 measurements per individual. The relationships between measures of stress-system function and depression were examined at the group level by means of mixed model analyses, and at the individual level by means of pair-matched comparisons. The analyses were repeated after adjusting for time-varying lifestyle factors by means of time-series regression analyses.ResultsCortisol and α-amylase levels were higher, the α-amylase/cortisol ratio larger, and the daily cortisol slope steeper in the depressed compared to the non-depressed group. Adjusting for lifestyle factors and antidepressant use reduced the associations under study. In 40%–60% of the matched comparisons, depressed individuals had higher cortisol and α-amylase levels, a larger α-amylase/cortisol ratio, and a steeper daily slope than their non-depressed match, regardless of adjustment.ConclusionsOur group-level findings were mostly in line with the literature but generalization to individuals appeared troublesome. Findings of studies on this topic should be interpreted with care, because in clinical practice the focus is on individuals instead of groups.

Investigation of an Immediate Effect of Bright Light on Oxygen Consumption, Heart Rate, Cortisol, and α-Amylase in Seasonal Affective Disorder Subjects and Healthy Controls

“…This finding nicely fits the fact that, contrary to the “classical” depression (which is usually associated with normal-to-increased α-amylase values [8]), SAD is characterized by depression with atypical features of lethargy and increased appetite/weight [16,18], as the latter better corresponds to a lower sympathetic tone. To be sure regarding the degree of the difference, the concentration should be ideally adjusted for salivary flow rate; while protein secretion is largely sympathetic, the flow rate is largely parasympathetic [7].…”

“…Cortisol was not found to be different between SAD and non-SAD but α-amylase was. Cortisol secretion is mainly under hormonal control, not under autonomic system control; although these systems are interrelated, the correlation between these 2 indices has not been found to be consistent [8]. …”

“…An effect of light on α-amylase, considered to be a marker of sympathetic nervous system activity [7,8], has been investigated, with negative results [9,10]. Findings on the immediate effect of light on cortisol values are inconsistent [summarized in [11]].…”

The Correlation of Sexual Dysfunction with Prenatal Stress and Quality of Life: A Path Analysis

“…The next event occurs in the hypothalamic-pituitary-adrenal axis and causes the secretion of corticotropin, adrenocorticotropin, and cortisol. Not only do these events lead to physiological responses, but also cause behavioral changes, including loss of appetite, reduced sexual activity, and increased feelings of depression, anxiety, aggression, and irritation (44,45).…”

Using Local Linear Models to Capture Dynamic Interactions Between Cortisol

“…By taking this approach, the highly dynamic nature of cortisol, depression and their causal relationship over time is neglected (e.g. Booij et al, 2015). It is questionable whether cross-sectional associations that are found at the inter-individual level (e.g.…”