High and low neuroticism predict different cortisol responses to the combined dexamethasone--CRH test.
BACKGROUND
Depression and posttraumatic stress disorder are both associated with altered function of the hypothalamic--pituitary--adrenal axis. Neuroticism is a strong predisposing factor for depression and probably also a risk factor for posttraumatic stress disorder. This study investigated whether young adults with high and low neuroticism scores show differences in hypothalamic-pituitary-adrenal axis regulation that might relate to their differential vulnerability to psychopathology.


METHODS
Neuroticism was measured with the Eysenck Personality Questionnaire in 258 students aged 18--25. Fourteen scoring in each of the upper and lower quartiles of the neuroticism distribution according to gender participated in a combined dexamethasone-corticotropin-releasing hormone test.


RESULTS
Low-neuroticism individuals showed a significantly greater cortisol response than high-neuroticism individuals.


CONCLUSIONS
The mechanism of this effect remains to be elucidated. High-neuroticism subjects may have a downregulated hypothalamic--pituitary--adrenal axis to prevent harmful overactivation. This is the first demonstration of a difference in hypothalamic--pituitary--adrenal axis regulation associated with neuroticism.
University of Oxford Department of Psychiatry, Warneford Hospital, Oxford, UK.
J M
JM
McCleery
G M
GM
Goodwin
D000328:Adult; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D003907:Dexamethasone; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D009497:Neurotic Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000503:physiopathology; D012720:Severity of Illness Index
D000893:Anti-Inflammatory Agents; D003907:Dexamethasone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone