Color & Control:

How Much of Addiction is Biological?

Addiction affects millions of people all over the world, and the implications for sufferers, their loved ones, and wider society can be devastating.

Addiction affects millions of people all over the world, and the implications for sufferers, their loved ones, and wider society can be devastating. Whether it’s alcohol, drugs, or gambling addiction affects people of all ages and from all cultural backgrounds.

In an effort to provide better care and outcomes for sufferers, researchers have long studied addiction in an attempt to figure out how it works. It’s a complex subject that can give rise to further questions, all of which must be answered if we want to eradicate the blight of addiction. Understanding addiction, whether it’s knowing what kindling is or how addiction affects the brain is key. How much of addiction is biological? Let’s find out.

What is Addiction?

Before we can discuss how much of addiction is biological, first we need to define exactly what addiction is.

Addiction is defined as the compulsive use of a substance or repetitive behaviour. Even if this use or behaviour is causing harm, be it physical, mental, or financial, addicts are unable to stop. There is an important distinction to be made between addiction and misuse. Someone who drinks a lot of alcohol on a night out with friends, and who experiences both positive and negative effects, would be said to be misusing the substance. However, if their alcohol use becomes compulsive and relapsing despite worsening negative effects, this would be classed as an addiction.

When we think of addiction, we often think of alcohol and drugs. While there are certainly among the most common types of addiction, there are others including gambling, eating, and shopping, as well as more recently observed types such as social media and internet addiction.

Addiction is characterized by a loss of control. Addicts are unable to stop themselves from repeating the same behaviour and will see various aspects of their life suffer as a result. Addicts may suffer health problems, financial difficulties, and a breakdown of social relationships, often a combination of all three.

A common misconception is that addiction is the result of choice and that addicts are ultimately responsible for the situation they find themselves in. This can lead to stigma and can make addicts unwilling or unable to seek out help. The more addiction is studied, the more we learn about the physical effects it has on the brain and the body.

While addiction can cause physical changes to the brain, biological factors can also play a role in how likely it is that someone will develop an addiction. Find out more below.

Biological Risk Factors

Our body chemistry and genetic make up who we are and influence things like our looks and our personalities. Genes are hereditary units made up of DNA and are passed from parents on to children.

As we study and learn more about addiction, we’re finding more and more links between genetics and addiction predispositions. One person may become addicted to a substance while another may not, with their particular biological make-up often the deciding factor.

For example, some alcohol addicts have been shown to have smaller-than-average amygdalae, which is a section of the brain that controls emotional responses and feelings such as cravings and desire.

Our genes also play an important role. Addicts may have specific genetic markers that make them more predisposed to repetitive compulsive behaviours such as alcohol or drug use. These genetic markers may be underlying and only triggered under emotional strain such as stress.

This is known as epigenetics; it’s the effect environmental factors can have on how genes are expressed. Research suggests that epigenetics could account for up to 60% of a person’s likelihood of being at risk of addiction.

One key indicator that points to a biological cause of addiction is the fact that addiction risks can be hereditary. While external environmental factors certainly play a role as well, there can be no denying that biology is key to a person’s likelihood of developing an addiction.

How Does Addiction Change the Brain?

In the past, addiction was viewed as a choice, with addicts perceived as weak or out of control. As we have learnt more about addiction, we’ve come to realize that it is in fact a chronic brain disorder that can have identifiable physical effects on the brain.

Our brains reward us when we participate in beneficial or healthy behaviours, such as eating, spending time with our loved ones, or exercising. To reward us, the brain releases a neurotransmitter called dopamine, which promotes feelings of happiness and satisfaction and motivates us to repeat the behaviour.

In addicts, this reward system is compromised and becomes a key part of compulsive, harmful behaviour. Some drugs can mimic neurotransmitters, while others encourage the brain to release more dopamine than it normally would.

Addicts will continually seek out substances to keep the brain flooded with dopamine, with tolerance building over time meaning more is needed to feel the same effect. Over time, the area of the brain that controls these feelings, the basal ganglia, changes, meaning addicts find it difficult to experience pleasure from anything other than a substance or behaviour.

Addiction can also change how the brain handles feelings of stress and fear. When not using, these feelings are amplified. This means addicts often begin using substances, not for their positive effects, but to stave off these potential negative effects.

Finally, addiction can damage the prefrontal cortex, which is an area of the brain that controls impulses and decision-making. This can make it even harder for an addict to recognize their condition and stop their behaviour.


Addiction is a serious condition that can have devastating effects on sufferers and those close to them. As it is studied more, we’re finding more and more links that suggest the root causes are biological, and that our genetic makeup can determine whether or not we will be at risk of developing an addiction.

Understanding addiction is vital. The more we learn about it, the better care and support we’ll be able to offer sufferers and the closer we’ll get to eradicating the problem.

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