Adrenocorticotropic Hormone (ACTH)

What’s covered?

Adrenocorticotropic Hormone (ACTH) is a peptide hormone produced by the anterior lobe of the pituitary gland in response to corticotropin-releasing hormone secreted by the hypothalamus. ACTH stimulates production and release of glucocorticoids (predominantly cortisol) from the adrenal cortex, which induces an increase in blood pressure and blood sugar, and a decrease in the immune system of the body. However, ACTH is not released from the pituitary gland in response to these conditions through hypothalamic action but instead to some stimulus that may be psychological or psychosocial (Dewhurst and Read 1978). Cortisol alleviates stress via 3 main mechanisms:

· It modulates the immune system.

· It activates the ‘fight-or-flight’ response.

· It acts on the brain and inhibits neurons that control anxiety.

While cortisol is known to have an impact on these functions, no one knows for certain what role it plays in the regulation of mood. More recently, research indicates that cortisol may have a role in the pathology of mood disorders and help explain why some people suffer from depression, while others do not (Mayo Clinic 2015).

While we offer ACTH tests, it is important to understand the broader implications of blood testing in our article on "Understanding blood tests".