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  • Lianna Lee, Researcher & Article Writer

Heroin and the Brain

Lianna Lee, Reseaarcher and Article Writer

The Brain, one of the most complex and important organs, controls our bodily functions and behaviours, from stimulating one’s heart beat, to helping us understand our world. Substance misuse is one of the many dangerous ways that can lead to damage in our brain.



What is Heroin?

Heroin is an opioid drug made from morphine, which is a natural substance made from poppy plants. People usually inject, sniff, snort, or smoke the substance, and it is highly addictive. The Drug Enforcement Agency classifies Heroin as a Schedule I drug, meaning that it is a substance ‘with no current accepted medical use and a high potential for abuse’.

How does Heroin work?

The brain naturally contains opioid receptors, and creates opioid chemicals automatically in response to discomfort and pain to try and relieve it. Although, these naturally occurring opiates do not last that long, and may not be enough to ease the pain. Heroin is basically a more potent version of these natural opioid chemicals in the brain. It binds to the same opioid receptors after entering the brain, and releases an influx of neurotransmitters such as dopamine, serotonin, and more. However, this is where the negative and damaging problems in the brain begin.

Unfortunately, once the brain encounters synthetic opioids, the production of natural opioids decreases, affecting the opioid receptors and the risk/reward system. This causes an imbalance of neurotransmitters, which may cause anxiety, aggression, and poor impulse control. The brain will begin to be chemically dependent on heroin, meaning that the individual will experience withdrawal symptoms when they try to stop using the drug. An increase in tolerance for Heroin will occur in the brain, so the individual will need larger doses of the drug to gain the euphoric effects, leading to addiction.

What else does Heroin do to the brain?

1. Harmful proteins form.

  • This causes structural alterations in the brain, alterations that are similar to those associated with Alzheimer’s disease.

  • When these changes occur in the brain, you may experience paranoia, personality changes, memory loss, depression, and many other symptoms.

2. White matter in the brain can deteriorate.

White matter: Brain and Spinal cord tissue that mainly consists of axons.

  • When you lose white matter in the brain this can negatively affect the ability to make decisions and form proper reasoning.

  • It can also make it harder for you to cope with stress and maintain your behaviour.

3. Long-term imbalances can be created.

  • As structural changes occur in the brain, this causes an imbalance in neurological and hormonal systems, leading to a reduction in sexual hormones.

  • This may cause chronic fatigue, depression, osteoporosis, and a loss of muscle mass. Neurological imbalance can also cause genetic disorders, dementia, seizures, Parkinson’s disease, and more.

Osteoporosis: A health condition that causes the weakening of bones, making them more fragile.

4. Vascular structure or blood vessels can be altered.

  • This can cause strokes, aneurysms, and other changes in blood flow of the brain that may damage it.

There are many more negative effects of Heroin usage on the brain, and Heroin is only one of the many drugs that can dangerously damage our brains. We must ensure we take the correct action by helping those around us who may be engaging in substance misuse. An example would be guiding them to get proper treatment at a drug rehabilitation clinic, before further damages cannot be reversed. And always remember, do not take any drugs.



How does heroin affect the brain?: Heroin's effects on the mind. (2021, July 13). American Addiction Centers.

How does heroin affect the brain? heroin and the brain. StoneRidge: Center for Brains. (2020, September 23).

Heroin (n.d.). US Drug Enforcement Administration.

Heroin drugfacts. (2021, June 30). National Institute on Drug Abuse.


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