The Hypothalamic-Pituitary-Adrenal (HPA) axis is one of the main physiological systems which allow the organism to respond to environmental “stress”. The HPA axis is influenced by early life experiences and is responsive to acute life events and furthermore has long been thought to be dysfunctional in mood disorders. Recent work has shown that subtle alterations in levels of corticosteroids (the main hormonal output of the HPA axis) may profoundly interfere with the actions of serotonergic antidepressants (Gartside et al, 2003). Corticosteroids may also be important for the cognitive impairment which is present in both unipolar and bipolar mood disorders (Porter et al, 2003; Thompson et al, 2005). Remission of certain domains of cognitive impairment may provide an important marker for remission in Mood Disorders (Gallagher et al, 2007). Lastly, the prospects of novel treatments for mood disorders which directly act on the HPA axis will be reviewed.
Keywords: mood disorders; HPA Axis; cognition; drug treatments.
References
(1) Gartside SE, Leitch MM, Young AH. Altered glucocorticoid rhythm attenuates the ability of a chronic SSRI to elevate forebrain 5-HT: implications for the treatment of depression.
Neuropsychopharmacology. 2003 Sep;28(9):1572-8.
(2) Porter RJ et al, Neurocognitive impairment in drug-free patients with major depressive disorder. Br J Psychiatry. 2003 Mar;182:214-20.
(3) Thompson JM et al, Neurocognitive impairment in euthymic patients with bipolar affective disorder. Br J Psychiatry. 2005 Jan;186:32-40.
(4) Gallagher P et al, Neurocognitive function following remission in major depressive disorder: potential objective marker of response? Aust N Z J Psychiatry. 2007 Jan;41(1):54-61.
(5) Young AH et al, Improvements in neurocognitive function and mood following adjunctive treatment with mifepristone (RU-486) in bipolar disorder. Neuropsychopharmacology. 2004 Aug;29(8):1538-45.
This post was submitted by Prof Allan Young.
