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What is addiction and how does it affect the brain?

Researcher & Writer: Ruka Arakaki

Illustrator: Shail Patel

What is addiction?

Addiction is where an individual has no control over doing, taking, or using something leading to a dangerous outcome. Common types of addiction are drugs, gambling, alcohol, and smoking (nicotine) but there are many other things one could easily be addicted to such as shopping, the internet, or work.

What causes addictions?

There are many reasons why people become addicted. Drugs, alcohol, and nicotine change the way one mentally and physically feels. The feeling gained from these substances can be enjoyable and promote one to continue using them in order to “feel good’.

With gambling, after winning, one may feel a rush of excitement and happiness making them want to keep playing in order to reach the mental “high” state. This can develop into a habit and can become very difficult to stop. Being addicted to something means experiencing withdrawal symptoms. Withdrawal symptoms are physical and mental symptoms a person experiences when they refrain from activities involving an addictive substance. Withdrawal symptoms can be unpleasant so in order to avoid these, individuals tend to continue using or doing what they crave. However, family studies that have included identical twins, fraternal twins, adoptees, and siblings suggest that there is possibly more than half a chance of becoming addicted to nicotine, alcohol, or drugs due to one’s genetics. Furthermore, genetics isn’t the only factor that could cause addiction the way one was brought up could be a crucial reason. If an individual grows up in an environment of substance abuse where older individuals participate in them, the individual may copy their “role model” and accommodate.

Symptoms of addiction

With addiction, one could experience multiple symptoms however they may vary for each person. Some symptoms include:

1. An inability to stop using a substance or activity: People may continue to use a substance or partake in an activity even if they wanted to stop.

2. Lack of control:

One may feel like they’ve lost all control over substance use or activity and often feel helpless.

3. Increased tolerance:

As one continues to use a substance, they manage to intake a higher dosage in order to feel the same euphoric effects as they did before.

4. Personal problems:

Addiction can affect multiple aspects of one’s life including their physical health, mental health, personal relationships, and career.

5. Withdrawal symptoms:

People with addictions experience withdrawal symptoms when they stop using a substance. This can be both physical and emotional symptoms. Physical symptoms include shaking, sweating, or vomiting. They may also become anxious or irritable.

How do substances affect the brain?

Drugs and alcohol affect three areas of the brain, the brain stem, the limbic system, and the cerebral cortex. When the substance chemicals reach the brain, they interfere with brain processing and can lead to changes in the functions of neurons and brain circuits.

Drugs imitate the brain’s natural chemical messengers hence over-simulating the brain’s “reward” circuit. The limbic system contains the brain’s “reward” circuit. The reward circuit combines a number of brain structures that control and regulate our capability of feeling pleasure. Typically, the reward circuit responds to feelings of pressure by releasing the neurotransmitter “dopamine”. The drug substances take control of the reward circuit forcing large amounts of dopamine to flood the system. The overload of dopamine is what causes the “high” or feeling of intense happiness (also referred to as euphoria) linked to drug use. Some drugs such as marijuana have chemical structures that imitate neurotransmitters that naturally occur in our bodies. The drugs can deceive our brain receptors, bind to them, and activate nerve cells. As these drugs do not function like natural neurotransmitters, the neurons result in sending abnormal messages through the brain.

Alcohol makes it harder for the brain areas controlling balance, memory, speech, and judgement to function properly hence resulting in a higher likelihood of injuries and other negative outcomes. Long-term heavy drinking causes changes in neurons such as reductions in their size. Alcohol misuse can also cause alcohol-induced blackouts. Blackouts are gaps in a person’s memory of events that occurred while they were intoxicated. These gaps occur when a person drinks enough alcohol causing a temporary blockage in the transfer of memories from short-term to long-term storage in an area of the brain called the hippocampus.

Addiction is a common problem but it isn’t untreatable. Hospitals can help monitor and provide therapy needed for those going through withdrawal. Rehabilitation is always an option where one is provided with structured counselling, education, and support. Rehabilitation services focus on helping people manage long-term addictions and live healthier lifestyles. If you have an addiction please remember to consult a professional regarding this to receive the treatment you need.


What is the impact of substances on the... Caron Treatment Centers. (n.d.). Retrieved April 22, 2023, from,strength%20of%20

U.S. Department of Health and Human Services. (n.d.). The reward circuit: How the brain responds to natural rewards and Drugs. National Institutes of Health. Retrieved April 22, 2023, from,relays%20electrical

Addiction. Cleveland Clinic. (n.d.). Retrieved April 22, 2023, from

U.S. Department of Health and Human Services. (n.d.). Alcohol and the brain: An overview. National Institute on Alcohol Abuse and Alcoholism. Retrieved April 22, 2023, from

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