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What Happens to the Brain during Addiction?

What Happens to the Brain during Addiction?

Drugs literally dominate the brain, because the brain doesn’t have an adequate defense against drugs.” ~ Michael Kuhar, The Addicted Brain: Why We Abuse Drugs, Alcohol, and Nicotine Way back in 1956, the American Medical Association declared that alcoholism – the addiction to alcohol – was a disease, not a moral failing, weakness, or character defect as so many people previously thought (and still think). In 2011, the American Society of Addiction Medicine (ASAM), based upon the consulted opinion of more than 80 experts, clarified the official definition of addiction as a “primary, chronic disease of brain reward, motivation, memory, and related circuitry.” Because it is now known that by hijacking the brain to foster compulsive substance abuse, addiction changes a person’s behavior and makes them powerless over their drug of choice, medical science is beginning to make groundbreaking discoveries about the disease that are revolutionizing our understanding of and response to the global drug problem.

Different Drugs Have Different Effects

Using or abusing and intoxicating substance does more than merely alter a person’s behavior – it literally can make physical and chemical changes within the brain that totally disrupt a person’s normal thought processes, impulse control, decision-making ability, and even their ability to distinguish between conscious choice and involuntary action. For example, when looking at MRI scans of the brains of users of different drugs, researchers found that:

  • The active ingredient in “magic mushrooms, psilocybin, slows the neural activity in the part of the brain that is responsible for creating a person’s sense of “self”.

Surprisingly, the drug also “jump-starts” new connections between areas of the brain that do not normally communicate with each other. In other words, it builds new informational connections.

  • A regular smoker of marijuana has a smaller orbitofrontal cortex – the part of the brain that helps people make decisions and process emotions – than a non-smoker. In possible compensation, the cross-brain connections become thicker.
  • It has long been known that drinking can affect a person physically – impaired memory, slurred speech, blurry vision, etc., but researchers have discovered that episodes of binge-drinking – downing four or more drinks in one two-hour sitting if you’re a woman, or five if you’re a man – affects the way the brain processes information in the long-term.

A 2014 study compared people who were dependent on alcohol with people who were, and found that the alcohol-dependent people took a much greater amount of time to perform the same task with the same level of accuracy as the non-dependents. It was also found that binge drinkers have to “recruit” new areas of the brain to help process information since the traditional regions become impaired and can no longer fully handle their necessary duties. Jodi Gilman, a clinical researcher at the Massachusetts General Hospital Center for Addiction Medicine, said: “Imagine the brain as an engine – you have to rev it up more to get the same work done.”

  • Cocaine affects the memory centers of the brain that help us remember where a pleasurable experience came from. The euphoric cocaine “high” creates pleasurable memories of such vividness that just seeing a picture of someone else using the drug can trigger cravings.

Regular exposure to cocaine changes the brain cells within the prefrontal cortex – the part of the brain that helps with inhibition control and decision-making.

  • Ecstasy strongly affects key areas of the brain, in a disturbing manner. Activity in the brain areas that are involved in how a person learns and remembers things is greatly impaired in chronic ecstasy users.

Using a simple test to see if participants could recall 15 unrelated words, chronic users scored far worse than non-users. More importantly, the longer and more frequently the individuals had used ecstasy over their lifetime, the more drastic the negative brain changes and results were. Worst of all, even former ecstasy users who had stopped taking the drug continued to have difficulties with memory and learning.

Even Using Substances One Time Matters

Most people can grasp that substance abuse can change a person and their behavior over time. What they may fail to realize is that drug abuse can begin to affect a person from the very beginning. For example, scientists have recently found evidence suggesting that cocaine can affect a person’s brain structure after just one dose. Similarly, methamphetamine, which is three times as powerful as cocaine, causes the release of up to 10 times the normal amount of dopamine. The rush from meth can last up to 12 hours, compared to cocaine’s two-hour high. The first few instances an individual uses methamphetamine, they make their decision in the prefrontal cortex of the brain – it is a choice they make consciously. However, perhaps as soon as only the third use, the hindbrain takes control, and the use of the drug  becomes an involuntary function. Jim Peck, of UCLA’s Semel Institute for Neuroscience and Human Behavior, states, “Meth actually changes your brain. Your brain elevates your need for the drug the same level as anything else you have to do to survive, like breathing.”

The Mechanics of Drug Addiction

Basically, an addiction develops because of the effect that an abused substance has on the brain’s reward centers. When human beings perform some action – for example, taking an illicit drug – that fulfills a basic survival needs or satisfies a desire, the neurotransmitter dopamine is released, creating a pleasurable feeling as a reward. Usually, these rewards are primarily reserved for actions that promote survival – eating, reproduction, etc. These pleasurable rewards come after an expenditure of effort and after the associated delay of making that effort. Addictive drugs are a shortcut to those rewards, because they trigger a massive amount of dopamine, “training” the brain that the use was an extremely pleasurable experience, and therefore, worthy of remembering and repeating. The human brain has not evolved naturally to be able to handle such a rush of dopamine, so the body shuts down the natural production of dopamine. After repeated drug abuse, the body becomes unable to naturally produce the neurotransmitter, meaning that the only way the addict can feel pleasure – or even normal – is to use the drug again to artificially stimulate dopamine production.

  • The nucleus accumbens becomes flooded with dopamine.
  • The hippocampus creates a pleasurable memory to “highlight” the activity.
  • The amygdala creates a conditioned response that can be triggered by certain stimuli that are present in the stored pleasurable memory.
  • When that recalled stimuli – or even regular, everyday stress – are experienced again, the conditioned response is tripped, and strong cravings for the drug and its effects are felt again, possibly leading to relapse.

Why Is All of This Important?

The more we know about the disease of addiction and how it affects us, the more weapons we can soon have at our disposal to battle the illness and its catastrophic consequences. Dr. Nora D. Volkow, M.D., Director of the National Institute on Drug Abuse, says it best – “At the National Institute on Drug Abuse, we believe that increased understanding of the basics of addiction will empower people to make informed choices in their own lives, adopt science-based policies and programs that reduce drug abuse and addiction in their communities, and support scientific research that improves the Nation’s well-being.”