Cortisol

Cortisol is the primary glucocorticoid hormone produced by the adrenal glands. As a product of the hypothalamic–pituitary–adrenal (HPA) axis (one of the main components of the human stress response system, discussed elsewhere in this volume), cortisol serves numerous psychobiological activities during times of normal (resting) activity and during times of perceived stress, as well as other biological functions, such as regulating blood pressure, glucose levels, and immune function. Furthermore, cortisol can be measured from saliva, making it a useful and noninvasive biological measure of stress functioning across the lifespan (from newborns to elderly populations).

There is evidence for both genetic and environmental influences on human cortisol levels, as well as evidence for atypical cortisol levels among children and adults with different forms of psychopathology. Environmental conditions ...