top of page
  • Writer's pictureKevin Phillips

Stress and the Brain

Updated: Jan 26

For hundreds of years people have talked about "alcoholism", "drug abuse" or "addiction" as a moral failing. A person drank too much or did not stop using psychoactive drugs because they were unrepentant pleasure seekers. For many years now, research into neurobiology was provided insight into Substance Use Disorder in terms of the brain and its dysregulation.

The brain consists of a complex network of cells that cluster together in different regions to serve a specific function. The frontal cortex, hypothalamus, amygdala, HPA (hypothalamic-pituitary-adrenal) axis, and vagus nerve are major components of the central nervous system that play crucial roles in regulating various physiological and emotional responses in the body. Here's an overview of their relationships:

Frontal Cortex:

The frontal cortex is a region of the brain responsible for higher cognitive functions, including decision-making, problem-solving, and social interactions . It plays a crucial role in moderating emotional responses and regulating behaviors based on social and cultural norms.



The hypothalamus is located at the base of the brain and serves as a link between the nervous system and the endocrine system. The endocrine system produces and releases hormones into the bloodstream to regulate various functions in the body such as body temperature, hunger, thirst, and sleep. This link makes the hypothalamus a key player in the stress response.



The amygdala is a part of the limbic system and is involved in the processing of emotions, particularly fear and pleasure. It plays a vital role in the formation and storage of emotional memories and in the modulation of the stress response. The amygdala processes emotions, particularly fear and the formation of emotional memories. During a traumatic event, the amygdala is activated to assess the emotional significance and potential threat. It helps in encoding emotional memories associated with the trauma.

In individuals with PTSD (Post-Traumatic Stress Disorder), there is evidence of heightened amygdala activity. This hyperactivity may contribute to heightened emotional responses and increased arousal. The amygdala's persistent activation can lead to an exaggerated fear response even in non-threatening situations, contributing to hypervigilance and emotional reactivity.


HPA Axis (Hypothalamic-Pituitary-Adrenal Axis is a complex neuroendocrine system that regulates the body's response to stress. The process begins in the hypothalamus, where CRH (corticotropin-releasing hormone) is released in response to stress. This stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then triggers the adrenal glands to release cortisol, a stress hormone that mobilizes energy and suppresses non-essential bodily functions during a stress response.


Vagus Nerve:

The vagus nerve plays a role in regulating heart rate, digestion, and other involuntary bodily functions. It also serves as a key player in the body's relaxation response, helping to counteract the stress response initiated by the HPA axis.

The relationship between these components is intricate. The frontal cortex provides cognitive modulation of emotional responses. It is where you make choices about what you are experiencing. The hypothalamus initiates the stress response through the HPA axis, the amygdala influencing emotional processing, and the vagus nerve contributing to the regulation of the overall autonomic nervous system. These interconnected systems work together to maintain balance and adapt to various environmental challenges.

Substance Use Disorder dysregulates this complex neurobiological system. It knocks it out of whack. A person living with SUD has learned to use substances as a means to relieve stress. Because the brain no longer functions in a healthy way, thr stress response is hyperactivated when a person enters withdrawal from not using the substance. To calm down, to alleviate this stress response, the user returns to substance use. Welcome to ghe merry-go-round of addiction.

In SUD treatment, we help the person in recovery learn alternative ways to address the stress response in their body to give their brains time to heal. The goal is to help the person identify the stress response in their body. We help them learn to manage stress without having to return to substance use just to get through the day.

People can heal. It takes time to get the brain back on line. In treatment, patients learn how to reduce the stress response in their bodies so their brains can return to healthy function and they can return to the joy of living their lives in healthy relationships with others.


Recent Posts

See All


The development of intrinsic motivation plays a crucial role in Substance Use Disorder treatment and recovery. Intrinsic motivation is the drive to engage in an activity for its inherent benefit, rath


bottom of page