Posted by jrbecker on April 19, 2004, at 10:08:27
Potential key HPA axis dysregulation feature in MDD identified
Psych Res 2004; 126: 1-13
Contrary to expectations, investigators have found that the characteristic feature of hypothalamic-pituitary-adrenal (HPA) axis dysregulation in patients with major depressive disorder (MDD) may be erratic cortisol secretion, rather than hypercortisolism.
"Dysregulation of the HPA axis is an important feature of MDD, but relatively little attention has been given to within-person variability of hormone secretion over time," observe Frenk Peeters (Maastricht University, The Netherlands) and colleagues.
To address this issue, the team took multiple salivary cortisol samples from 47 outpatients with MDD and 39 mentally healthy controls over a 6-day period.
Overall, there was no evidence for daytime hypercortisolism in the depressed outpatient group relative to controls, although self-reported symptom severity was associated with higher cortisol levels.
The researchers report that "a more striking finding" was the erratic pattern of cortisol secretion among MDD patients, as evidenced by lower cortisol autocorrelations, in comparison with controls.
They note in the journal Psychiatry Research that these secretions were particularly erratic among patients with more severe or recurrent episodes. This finding is consistent with the hypothesis that "repeated episodes result in more severe, perhaps structural, changes in HPA axis function," the team says.
Although the underlying cause of this increased intraindividual variability remains unclear, Peeters et al suggest that vulnerability factors may combine with clinical characteristics to produce a spectrum of HPA axis disturbances in MDD. The subtle changes in cortisol secretion seen in their study may represent one of the initial manifestations of this spectrum of disturbances.
"Longitudinal studies in MDD might therefore be useful for evaluating the prognostic value of cortisol secretory variability, as well as the effects of pharmacotherapy, other treatments, and clinical recovery on this aspect of HPA axis dysfunction," the researchers conclude.
poster:jrbecker
thread:337707
URL: http://www.dr-bob.org/babble/20040417/msgs/337707.html