Posted by dessbee on December 18, 2006, at 7:34:06
In reply to Re: Corticotropin Releasing Factor, posted by stargazer on December 15, 2006, at 20:30:07
It seems like it is not a reliable test for diagnosing depression.
Found this:
"The sensitivity of the DST (rate of a positive outcome, or nonsuppression of cortisol) in major depression is modest (about 40%-50%) but is higher (about 60%-70%) in very severe, especially psychotic, affective disorders, including major depression with psychotic as well as melancholic features, mania, and schizoaffective disorder."
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=3310667
"This test is performed when overproduction of cortisol is suspected. The low-dose test can help differentiate healthy people from those who produce too much cortisol. The high-dose test can help determine if the abnormality is in the pituitary gland (Cushing's Disease).
The secretion of ACTH from the pituitary gland is normally regulated by the level of cortisol in the blood plasma. ACTH stimulates the adrenal cortex to produce cortisol. As plasma cortisol levels increase, ACTH secretion is suppressed. As cortisol levels decrease, ACTH increases.
Dexamethasone is a synthetic steroid similar to cortisol, which suppresses ACTH secretion in normal people. Therefore, giving dexamethasone should reduce ACTH levels, resulting in decreased cortisol levels. People with pituitary glands which produce too much ACTH will have an abnormal response to the low-dose test, but a normal response to the high dose."
poster:dessbee
thread:713761
URL: http://www.dr-bob.org/babble/20061217/msgs/714740.html