Which statement about cortisol release and the hypothalamic-pituitary-adrenal axis in chronic stress is true?

• A. Chronic Stress Can Lead to Excessive Cortisol Production and Increased HPA Axis Reactivity.
• B. Chronic Stress Reduces Cortisol Production Across the Board.
• C. Cortisol Is Unaffected by Nonthreatening Stimuli.
• D. Lower Cortisol Reactivity Is Always Protective Against Social Challenges.

Answer: (A)

Chronic stress often drives sustained activation of the hypothalamic-pituitary-adrenal axis, leading to higher cortisol output and heightened reactivity to stressors. The hypothalamus releases CRH, which prompts the pituitary to secrete ACTH, driving the adrenal cortex to produce cortisol. Cortisol mobilizes energy and modulates various body systems, but with ongoing activation the feedback control can become dysregulated. Receptors may become less sensitive, the normal daily rhythm can flatten, and baseline cortisol can remain elevated or the response to new stressors can become exaggerated. This pattern helps explain why chronic stress is linked to higher cortisol levels and a more reactive HPA axis. The other statements don’t fit typical physiology: cortisol isn’t universally reduced with chronic stress, nonthreatening stimuli can still influence cortisol under chronic stress, and lower reactivity is not reliably protective in social challenges.