Allostasis and Addiction

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Your brain, in all its complexity, relies on an intricate balance of chemicals and interactions. When the brain is working correctly, we adapt and behave appropriately within our environments, learning and adjusting as necessary. When stressors upset this balance, the brain adapts to them in a process called allostasis. Addiction is one such stressor, causing chemical changes that move the brain from homeostasis to allostasis and disrupt its normal functioning.

What Is Homeostasis?

Homeostasis is your body's natural state of balance. The brain oversees the body's homeostasis, making adjustments to maintain a healthy, functioning system. In homeostasis, your brain is able to respond and adapt to its environment smoothly and constructively.

What Is Allostasis?

Allostasis (/ˌaləˈstāsis/) is the state your body enters as it seeks to restore balance. In the brain, this means that important chemicals are out of balance, and its normal functions are disrupted.

How Addiction Affects Homeostasis

Addiction, whether to drugs or to alcohol, disrupts homeostasis and interferes with the body's ability to adapt to change. When your brain has difficulty achieving its ideal balance, it adjusts to cope with the addictive substances' reactions. It then creates a new setpoint to account for the added stimulation; allostasis is the process by which the brain creates this new balance point.

Consequences of Allostasis

Your brain is incredibly adaptive, but that ability to create a new balance point through allostasis can change how it functions. The change in the balance point triggers particular behaviors and urges, including:

  • A need for the addictive substance: The new brain chemistry makes obtaining the drug the most important goal, regardless of consequences. This can cause people to behave in harmful ways, such as hurting themselves or others, bankrupting themselves, or committing crimes to get drugs.
  • Difficulty quitting: Ending the addiction is extremely hard, as the brain's new balance point is dependent on the drug's influence.
  • Lack of Interest in other activities: Feeding the addiction becomes all that matters; other priorities, such as work and family obligations, fall by the wayside.

Once homeostasis has been disrupted and allostasis achieved, the brain requires the addictive substance to maintain this new balance point.

Returning to Homeostasis

Because of the brain's new state of homeostasis, you might not realize that your body has shifted and that you have become addicted to a substance such as alcohol, caffeine, cannabis, hallucinogens, inhalants, opioids, sedatives, stimulants, or tobacco.

Regardless of the substance, mental health professionals use four key criteria to identify a substance use disorder:

  • Impaired control: Due to homeostasis, you may ingest more than you intended or be unable to stop. You may also experience cravings so severe they override any other feeling.
  • Social impairment: Regardless of how your addiction harms others, you continue to engage in substance abuse.
  • Risky use: Despite being aware of the potential for physical harm, you may continue to take drugs. You may be so desperate to get your next fix you will put yourself at risk to get it.
  • Tolerance and withdrawal: Through tolerance, you will need more and more of the substance to get the same effects. You also may experience withdrawal symptoms if you don't get the substance you crave.

To restore health, you must reestablish your body's normal homeostasis—your body's natural setpoints in the absence of foreign substances. This entails treatment of the substance use disorder, typically through psychological and sometimes medication therapy.

When you are addicted to a substance, you are continually overstimulating parts of the brain, making it more difficult for your body to maintain balance.

A Word From Verywell

A substance use disorder causes the body to leave homeostasis and enter allostasis. The brain is remarkably adaptable, however; thanks to its neuroplasticity, you can recover from addiction and return your body to homeostasis.

If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

Frequently Asked Questions

  • What body systems does allostasis affect?

    Allostasis can affect any or all of the body's major systems, from neuroendocrine and cardiovascular to immune and metabolic systems. It's a state of disruption and stress as the body seeks a return to homeostasis, or balance.

  • What is allostasis as it relates to stress?

    Allostasis is your body's response to stress, whether physical or emotional. Your allostatic load—how much stress you are experiencing—can affect the functioning of your neuroendocrine, cardiovascular, immune, and metabolic systems.

  • How long can brain changes last after drug addiction?

    In the case of an alcohol use disorder, some parts of the brain can begin healing within a week of the last drink with alcohol; other parts can take months. With a drug use disorder, the chemical changes can begin to reverse in about 90 days of abstinence, but complete recovery can take a year or more, depending on the substance, severity, and length of the addiction.

3 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Roh E, Song DK, Kim MS. Emerging role of the brain in the homeostatic regulation of energy and glucose metabolismExp Mol Med. 2016;48(3):e216. doi:10.1038/emm.2016.4

  2. Ramsay DS, Woods SC. Clarifying the roles of homeostasis and allostasis in physiological regulationPsychol Rev. 2014;121(2):225–247. doi:10.1037/a0035942

  3. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. 5th ed., American Psychiatric Association, 2013.

Additional Reading
  • American Psychiatric Association. Diagnostic and Statistical Manual of Mental Illnesses, 5th edition. 2013.
  • Horvarth, T. "How Does Addiction Affect the Brain?" MentalHelp.Net. 2016.

By Elizabeth Hartney, BSc, MSc, MA, PhD
Elizabeth Hartney, BSc, MSc, MA, PhD is a psychologist, professor, and Director of the Centre for Health Leadership and Research at Royal Roads University, Canada.