Is addiction genetic? Understanding the role of nature and nurture

When patterns of addiction form in a family, are they the result of genes (nature), environment (nurture), or a combination of the two?

Twin and adoption studies suggest that genes account for 40% to 60% of a person’s risk of developing an addiction. However, having a family history of addiction doesn’t mean that you, or your children, will inevitably experience the same struggles.

A mix of genetics, environment, life experiences and mental health shapes addiction. Understanding these influences can help you make sense of your own risks — and more importantly, take steps to protect your wellbeing.

What does it mean for addiction to be genetic?

When it’s said that addiction can be genetic, it means that certain genes can influence brain chemistry, decision-making and how the body responds to substances. 

• Genetics refers to specific genes that may make some people more sensitive to the effects of alcohol or drugs, or more prone to developing habits
• Heredity describes how those genes are passed down through families

Having a genetic predisposition means your risk of developing an addiction may be higher, but it’s not a guarantee. This is similar to conditions like heart disease — family history increases risk, but lifestyle and environment make a huge difference.

Is alcohol addiction hereditary?

Alcohol is the substance most often studied in relation to heredity. Certain genes can influence how our bodies process alcohol and how rewarding we find it.

If a parent or sibling has experienced alcohol dependence, your risk of developing it too may be higher, but family history is just one part of the picture. How you’re brought up, the environment around you, how you cope with stress, and the level of access you have to alcohol can all have a major impact too.

What develops is a complex and nuanced picture for each individual. 

Join our expert psychiatrist, Priory's Dr Victoria Chamorro, as she outlines how hereditary addiction works.

Genetics vs environment in addiction

While genetics can increase your vulnerability to addiction, the environment you live in can also play a major role in whether addiction develops. 

These two factors are deeply connected, and understanding the balance between them can help people make sense of their own risks.

Early exposure to substance or behaviour

Growing up in a home where alcohol or drugs are easily available can normalise their use, as can early exposure to a behaviour like gambling. Early experimentation, especially during adolescence when the brain is still developing, increases the likelihood of forming addictive patterns.

Trauma and stress

Difficult life experiences, such as abuse, neglect, or high levels of ongoing stress, can make people more likely to turn to an addictive behaviour as a coping mechanism. Even if someone has no genetic predisposition, trauma alone can raise the risk of addiction.

Social and peer influences

The attitudes and behaviours of friends and social groups matter. Being surrounded by peers who drink heavily, use drugs or engage in an addictive behaviour regularly can encourage similar behaviour, while positive social networks can act as a protective factor.

Accessibility of alcohol and drugs

Practical access can also play a role. Someone genetically predisposed to addiction may never develop a problem if the substances or behaviour can’t be accessed. But if you have the means to access the substance or behaviour, it can combine with that increased genetic risk to lead to addiction.

The gene–environment interaction

Genes and the environment interact. A genetic vulnerability may only be triggered in certain environments — but positive, protective environments can help prevent addiction, even when there is family history.

Other risk factors that influence addiction

Beyond genetics and the environment, several other influences can increase the likelihood of addiction:

• Suffering from mental health conditions such as depression, anxiety or post-traumatic stress disorder (PTSD)
• Personality traits like impulsivity or sensation-seeking
• Family and social dynamics, including conflict or developing unhealthy behaviours
• Socioeconomic stress, such as financial difficulties or lack of support

Addiction is multifactorial. It’s rarely caused by a single factor alone, and each individual will have a different story to tell about how their addiction developed.

What can you do if addiction runs in your family?

If you know addiction is part of your family history, there are practical steps you can take to reduce your risk:

• Adopt strategies to cut down on alcohol and drugs 
• Speak to a GP or therapist early if you find yourself struggling
• Share your family history openly with healthcare professionals
• Develop healthy coping strategies such as exercise, mindfulness or supportive relationships
• Build strong support networks with friends, family or community groups like Adfam

Getting support for addiction

If you or a loved one are already struggling, it’s important to remember that help is available. Addiction is treatable, and recovery is possible regardless of family history.

At Priory, we offer a wide range of evidence-based treatments for alcohol, drug and behavioural addictions. Our services include outpatient therapy, inpatient rehabilitation and aftercare support.

You don’t have to face addiction alone. Learn more about our addiction treatment services or explore our Break the Chain campaign to understand how support can change the future for families.