Adrenocorticotropic hormone (ACTH) is a hormone from the anterior pituitary that signals the adrenal glands to release cortisol. In Intro to Psychology, it shows how the body turns stress into a hormone response.
Adrenocorticotropic hormone, or ACTH, is a hormone made by the anterior pituitary in Intro to Psychology when you study the endocrine system. Its main job is to tell the adrenal glands, especially the adrenal cortex, to release cortisol.
ACTH sits in the middle of the stress pathway called the HPA axis, which stands for hypothalamus, pituitary, adrenal glands. The hypothalamus starts the chain by sending a signal to the pituitary, and then the pituitary releases ACTH into the bloodstream. That makes ACTH more than a simple body chemical, it is a messenger that helps convert a mental or physical stressor into a hormonal response.
Cortisol is the hormone most often linked to ACTH. When cortisol rises, it helps the body mobilize energy, increase alertness, and handle short-term stress. That can be useful if you are taking a hard quiz, running to catch a bus, or reacting to a sudden problem. But if ACTH stays elevated for too long, cortisol can stay high too, and chronic stress can affect sleep, mood, immunity, and weight.
ACTH is controlled by negative feedback. Once cortisol levels get high enough, the hypothalamus and pituitary reduce their signaling, which lowers ACTH production. This keeps the stress response from running nonstop. If that feedback loop is off, the body may have trouble returning to baseline after stress.
For Intro to Psychology, the big idea is that ACTH links the brain and the body. You do not just think stress, and you do not just feel it in your body, the endocrine system helps turn the two into one coordinated response.
ACTH matters because it gives you a concrete example of how psychology connects behavior and biology. When a class talks about stress, emotion, or arousal, ACTH helps explain why a stressful event can lead to real physical changes, not just a feeling of pressure.
It also shows how the endocrine system works as a chain of signals instead of one isolated gland. The hypothalamus starts the response, the anterior pituitary releases ACTH, and the adrenal glands respond by producing cortisol. If you can trace that sequence, you can make sense of stress-related questions, hormone charts, and scenarios about chronic stress.
ACTH also connects directly to negative feedback, which is a recurring idea in psych and biology. Many hormone systems are built to self-correct, so understanding ACTH helps you predict what happens when cortisol rises, when stress continues, or when the body fails to reset after a challenge.
In mental health units, ACTH gives useful background for discussions of anxiety, sleep disruption, and long-term stress effects. It is not the whole story, but it is one of the clearest examples of how a hormone can shape both body state and behavior.
Keep studying Intro to Psychology Unit 3
Visual cheatsheet
view galleryHypothalamus
The hypothalamus is the part of the brain that starts the stress signal before ACTH is released. It acts like the control center that tells the pituitary to begin the HPA axis response. If you are tracing the pathway, the hypothalamus comes first, then the anterior pituitary, then the adrenal glands.
Anterior Pituitary
ACTH is made and released by the anterior pituitary, so this gland is the source of the hormone itself. In endocrine questions, the pituitary is often called the master gland because it sends out hormones that control other glands. ACTH is one of the best examples of that control function.
Cortisol
Cortisol is the hormone ACTH tells the adrenal glands to release. If ACTH rises, cortisol usually rises too, which is why the two are often discussed together in stress responses. Cortisol is also the hormone that feeds back to slow down ACTH when the body no longer needs the stress response.
Negative Feedback
Negative feedback is how the body keeps ACTH and cortisol from staying too high. When cortisol levels rise, they signal the hypothalamus and pituitary to reduce hormone release. That feedback loop is one of the easiest ways to understand how the endocrine system returns the body to balance after stress.
A quiz question or short-answer prompt may ask you to trace the stress pathway from the hypothalamus to the anterior pituitary to the adrenal glands. Your job is to identify ACTH as the pituitary hormone in the middle and explain that it triggers cortisol release. You may also be asked what happens when cortisol is high, and the answer is negative feedback, which lowers ACTH output. If you see a scenario about chronic stress, think about how repeated ACTH and cortisol release could affect sleep, mood, immune response, or weight. Diagram questions often test whether you can place ACTH in the HPA axis instead of confusing it with the hormone made by the adrenal glands. A good response uses the chain, not just the definition.
ACTH and cortisol are easy to mix up because they work together in the stress response, but they are not the same thing. ACTH is the signal from the anterior pituitary, while cortisol is the hormone released by the adrenal glands after that signal. If a question asks which one triggers the response, choose ACTH. If it asks which one circulates as the stress hormone, choose cortisol.
ACTH is a hormone from the anterior pituitary that tells the adrenal glands to release cortisol.
It sits in the middle of the HPA axis, which links the hypothalamus, pituitary, and adrenal glands.
ACTH helps explain how psychological stress turns into a bodily hormone response.
High cortisol feeds back to lower ACTH, so the system can reset after the stress passes.
Chronic ACTH and cortisol activation can show up in stress-related health and mood problems.
ACTH is a hormone made by the anterior pituitary that signals the adrenal glands to release cortisol. In Intro to Psychology, it comes up in the endocrine system and stress response because it helps explain how the body reacts to pressure.
No. ACTH is the messenger hormone from the anterior pituitary, and cortisol is the hormone released by the adrenal glands after ACTH sends the signal. They are linked in the stress response, but they do different jobs.
ACTH is the middle step in the HPA axis. The hypothalamus starts the signal, the anterior pituitary releases ACTH, and the adrenal glands respond by making cortisol. That chain is the core pathway to know for stress-related questions.
ACTH matters because repeated stress can keep the HPA axis active too long. When that happens, cortisol may stay elevated, which is linked to sleep problems, immune suppression, mood changes, and other effects that show up in psychology discussions of chronic stress.