Brain and Body

Addiction Transforms the Brain in Three Stages, According to Scientists

February 1, 2016 | Kelly Tatera

Man smoking a cigarette

A little more in depth than “it’s a disease.”

Experts have been arguing for a long time that addiction is a disease, but that’s a pretty vague statement. Both cancer and Alzheimer’s are diseases, but they obviously spread due to totally different mechanisms and have completely different effects on the brain and body.

Now, in a new paper published in the New England Journal of Medicine, researchers have presented a model of addiction broken down into three key stages, elucidating how the disease changes human neurobiology.

The authors propose that each of these stages affects an individual’s behavior by altering the way he or she reacts to stress, as well as changing the ability to have control over certain actions.

In order to better treat people with the disease, it’s important to fully understand what’s going on in the brain of someone who suffers from it. Simply saying “it’s a disease” does not suffice, according to Dr. Nora Volkow, director of the National Institute on Drug Abuse and the lead author of the new review.

SEE ALSO: What Happens When a Baby Is Born Addicted to Drugs?

People are told addiction is a disease of the brain, but don’t really understand what that means, Volkow told Live Science. She compares this to saying that “diabetes is a disease of the pancreas” — this explanation doesn’t give people a clear understanding of how the disease works in a person’s body.

In the new review, the authors lay out a three-stage framework of how addiction affects the brain’s biology:

1. Binge and intoxication

This is how it all begins — people take a drug and it makes them feel euphoric.

The euphoria experienced when consuming addictive drugs is caused by the release of dopamine — the same pleasure-causing neurotransmitter that is released when you eat or have sex. Unlike these natural stimuli, however, the more you consume addictive drugs, the more dopamine is released, so you never feel as if you’ve had enough.

Over time, the brain is conditioned to obsessively seek out that burst of dopamine. Strong connections form between euphoria and memories of using the drug (places, people, and objects associated with the drug). These brain connections are responsible for the intense cravings that occur even after a person stops using the drug.

2. Withdrawal and negative affect

In some people, intoxication can change the brain connectivity in such a way that they feel distressed and crave the drug when it’s not in their system. Volkow says that one of the most important functions of the human brain is to learn how to get out of stressful situations, like eating to get rid of the feeling of hunger.

When someone is repeatedly exposed to a drug, he or she quickly learns that the distress can be relieved by consuming more of the drug. This is what leads to the next stage, when the brain deals with those negative feelings of withdrawal.

If an individual is vulnerable to addiction, this can ultimately create a feedback loop between intoxication and withdrawal, explains Volkow. “You get high, you feel great, you crash, you feel horrible" and eventually the brain learns that the drug of choice will soothe the feelings of distress.

The brain’s connectivity changes in such a way that leads to stress and cravings during the second phase.

3. Preoccupation and anticipation

The final stage of the brain’s changes throughout the process of addiction happens when changes occur in the prefrontal cortex of the brain, which is responsible for the “executive processes” like decision making and self-regulation, according to the paper.

This third phase changes a person’s brain circuitry by decreasing the ability to resist strong urges and follow through on certain decisions, the authors say.

SEE ALSO: These are the Neurons that Make You Crave Booze

Volkow notes that these three stages of addiction aren’t necessarily distinct in every addict — they can blend in with one another, especially the stages of withdrawal and anticipation or cravings, she says.

The researchers also clarify that there’s no specific “threshold” of exposure to a drug that would cause a person to get addicted if it was surpassed, Volkow told Live Science. Addiction is an experience that can vary greatly from person to person.

Nonetheless, it’s extremely important to understand what’s actually going on in the brain during the different phases of addiction in order to treat it. The researchers hope this review will help physicians treat addiction as well as lead researchers to develop new medications to combat alcoholism.

While most people have finally gotten on board with the notion that addiction is a disease instead of a personal choice, it’s critical to understand how the disease takes over.

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