Heroin's Effects on the Brain

What effects can heroin have on the brain? Learn about the brain damage and chemical changes that heroin creates and find out if the damage is reversible.

What heroin does to the brain explains why people feel the euphoric rush or high they describe, but it can also be alarming to look at just how heroin affects the brain.

There are many ways heroin affects the brain, body, emotions and the life of someone who uses it. Understanding what heroin does to the brain can help empower you to either avoid ever using the drug or take the necessary steps to receive treatment if you’re already using it.

The following provides an overview of what heroin does to the brain and how that then translates to the behaviors, addictions and lifestyle changes that often occur in people.

How Heroin Works

First, heroin is a central nervous system depressant, as are other opioids, including prescription painkillers. When you take heroin, it breaks down into different chemicals that bind to opioid receptors in your brain. The same is true of drugs like codeine and morphine. Your body produces its own natural opioids as well, but it’s nothing compared with what happens when you take a drug like heroin.

Heroin use changes how you perceive and feel pain, but it also causes an increased sense of pleasure and well-being because a flood of dopamine is released into your body. These extremely high dopamine levels are what’s responsible for the high created by heroin.

How heroin breaks down in the body depends on the route of administration, or how you use the drug. If heroin is taken orally, then it passes through the liver and breaks down into morphine before it reaches the brain. If you inject, smoke or snort heroin, the drug does not pass through the liver. Instead, the heroin goes straight to the brain, where it immediately breaks down into morphine and other chemicals called 6-MAM and 3-MAM before it binds to the brain’s opioid receptors. When morphine and these chemicals bind to the opioid receptors, a euphoric high is felt.

The areas of your brain impacted by heroin are the ones responsible for controlling your reward pathways and they include the frontal cortex, nucleus accumbens, the ventral tegmental area, and the locus coeruleus, which is responsible for dependence and withdrawal symptoms. These are the circuits in your brain responsible for creating a sense of pleasure when you engage in activities like eating or sex.

If you were to eat a great meal, the same areas of your brain would be triggered as when you take heroin, but the response to heroin is so heightened and unnatural that it changes to way your brain communicates, ultimately “rewiring” it in some ways.

There are estimates showing using heroin can increase the dopamine levels in your body by as much as ten times more than what’s normal.

Tolerance and Dependence

Also, the key to understanding what heroin does to the brain is looking at the concept of physical tolerance. Tolerance to heroin occurs after you’ve been exposed to opioids for a while and, as a result, you’ve had a consistently raised dopamine level.

Your body adjusts to that level and the presence of the drug, which leads to dependence. As dependence happens, your pain threshold is lower, so you respond with more sensitivity to pain stimuli, and your pathways in the brain become overactive. That leaves your body with the feeling that you need to maintain your heroin use to feel normal. There are some studies that show the ways heroin affects the brain can start happening after only using the drug a few times.

When dependence occurs, you are at risk of experiencing withdrawal symptoms if you stop using the drug. If you don’t take the amount of heroin that your body now thinks that it needs, you will start feeling withdrawal symptoms. Since the presence of these increased dopamine levels has become your new normal, you won’t feel the same high you did initially with heroin. It takes larger doses to feel anything.

What Heroin Does To The Brain in the Long-Term

So what about what heroin does the brain in the long-term?

When you’ve used heroin for a long time, it starts to affect your prefrontal cortex, and also the temporal lobe of your brain. These are parts of your brain responsible for memory, decision-making, self-control of your behavior and critical thinking.

Some of the changes in your brain with long-term heroin use may result in the inability to control your behavior, problems processing emotions, memory problems and difficulty making decisions. What heroin does to the brain in the long-term can also include reducing your reasoning and problem-solving abilities, and it can make activities like planning ahead and interactions with other people difficult. Even if you stop using heroin, your brain can remember the changes, which may cause you to experience drug cravings and setbacks.

Some studies have shown that these changes in the brain start to appear very soon after the start of chronic heroin abuse. Other types of injuries can occur when you are impaired by the drug. Additionally, brain damage can be seen in people who have overdosed on heroin. This kind of brain damage isn’t due to the overdose, but because of the lack of oxygen to the brain (heroin slows down your breathing).

It’s important for people to realize how severe what heroin does to the brain can be, and it doesn’t take years of abuse for the drug to take its toll on the brain. It can happen relatively quickly and can be difficult to reverse.

If you or a loved one live with addiction or are using drugs recreationally and want to stop, The Recovery Village® can help. Reach out to one of our representatives today to learn how you can start on your path to recovery.

Editor – Thomas Christiansen

With over a decade of content experience, Tom produces and edits research articles, news and blog posts produced for Advanced Recovery Systems. Read more

Medically Reviewed By – Benjamin Caleb Williams, RN

Benjamin Caleb Williams is a board-certified Emergency Nurse with several years of clinical experience, including supervisory roles within the ICU and ER settings. Read more