Hypothalamic-pituitary-adrenal axis (HPA axis)

The **hypothalamic-pituitary-adrenal (HPA) axis** is a major neuroendocrine system comprising the hypothalamus, pituitary gland, and adrenal glands. It orchestrates the body's response to stress by regulating the release of hormones such as corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and cortisol. Activation of this axis helps maintain homeostasis during acute stress by mobilizing energy stores and modulating immune responses. However, chronic or dysregulated activation is associated with various pathologies including mood disorders, metabolic syndrome, cardiovascular diseases, and immune dysfunction[1][2][4][5]. The HPA axis itself is not a single molecular target but rather a physiological pathway; thus it does not fit standard definitions for drug targets like receptors or enzymes. **Note:** This entry is considered *incorrect* as a therapeutic target because "Hypothalamic-pituitary-adrenal axis activation" refers to an entire physiological pathway/system rather than a discrete molecule or receptor that can be directly targeted by drugs[1][4]. Drugs may act on components within this system—such as CRH receptors or glucocorticoid receptors—but not on "axis activation" itself.

Other names

Hypothalamic–pituitary–adrenal axisHPA axisHTPA axis