May 5, 2025

Understanding drug and alcohol addiction (dependence)

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No one starts using alcohol and other drugs (AOD) with the intention of becoming dependent.1

While most people use AOD without ever experiencing dependence, we know it affects around 1 in 30 Australians in any given year.2,3

In this article, we cover what dependence means, how it affects the brain and the physical and mental impacts.

We also discuss what increases and decreases a person’s risk of dependence and the role of social connection in recovery.

What’s the difference between addiction and dependence?

Language around AOD use has changed over time. The term addiction, which comes from the Latin word ‘enslaved by’ or ‘bound to’, emerged in the 1900s.1,4

In the 1960s, the World Health Organization (WHO) introduced ‘dependence’ to replace addiction, because it carried less negative connotations and better described people’s experiences.4

Dependence includes both physical and psychological aspects of AOD use. Addiction refers mainly to the psychological aspects, which goes beyond AOD use to behaviours like gambling, gaming or social media use.4

While the WHO’s recommendations came into effect over 60 years ago, the term addiction has seemed to stay. Now, dependence and addiction are often used by many people to describe the same thing.4

How alcohol and other drugs hijack the brain’s reward pathways

Dependence on alcohol and other drugs is a health condition, where a person is unable to control or stop using a substance even though it’s causing harm.5,6

It impacts the parts of the brain that control reward, stress and self-control.

Most substances trigger the brain’s rewards system – releasing a flood of neurochemicals like dopamine that initially make us feel good.1

Over time, with more frequent and continued use, this feel-good factor gets harder to achieve as the brain develops tolerance.7

When someone experiences tolerance, increasing the dose and/or frequency of drug use is needed in order to get the same dopamine ‘high’, or other effects such as pain and stress relief.1,7

This is usually when cravings, urges and the compulsion to take the drug or drink can take over.7

People who experience AOD dependence often feel like they need AOD to go about their normal activities like working, studying and socialising, or just to get through the day.4

It becomes a problem when the behaviour continues even when it’s harmful to the person, their family, and other important areas of life.

And, trying to reduce or stop use after a long time can be very challenging because the mind and body needs to get used to functioning without AOD.

The physical and mental impacts of alcohol and other drug dependence

While substance dependence and behavioural addictions have a lot in common, being dependent on AOD can have a few specific impacts.

These range from short and long-term, including:

  • sleep problems
  • cognitive and memory problems
  • reduced immunity leading to more colds and flu
  • chronic health conditions like cancer, heart disease, stroke, liver problems and osteoporosis
  • dental health problems
  • blood-borne viruses from using shared injecting equipment
  • mental health conditions
  • psychosis
  • overdose.8-10

Substance dependence can also lead to changes to the areas of the brain that control judgement, decision-making and behaviour control.9,11 These impacts can help explain why it can be difficult for some people to reduce or stop their use.9

Why do some people experience dependence on alcohol and other drugs and others don’t?

People use alcohol and other drugs for many reasons – to relax, for enjoyment, to improve focus, to avoid physical or emotional pain, to fit in, or to deal with grief, anxiety or trauma.12,13 And, the majority of people who use these substances don’t experience dependence.14

While there’s still a lot we don’t know, we do know dependence affects people from all walks of life and there’s no single cause.

We also know there are certain factors that put some people at an increased risk.15-17 These include:

  • Genetics
    Genetics play a major part in a person’s risk of developing alcohol and other drug dependence. If you have a parent or family member who has experienced dependence, then you may be at a higher risk of experiencing dependence too.
  • Environment
    Home, school and social environments can also increase the risk of AOD harms and dependence.  These risk factors include:
    • low academic achievement
    • poor social skills
    • favourable parental attitudes towards AOD
    • easy access to AOD through friends and family.
      Experiencing childhood trauma such as domestic violence, sexual assault or poverty can all also increase a person’s risk.
  • Age
    The younger someone is when they begin using AOD drugs, the greater their risk of developing a dependence later in life.

Factors that reduce your risk of dependence on alcohol and other drugs

Just as risk factors can increase the likelihood of substance use and dependence, other factors can reduce these risks. These protective factors include:

  • parental / caregiver involvement in their child’s life
  • strong and positive bonds with parents and caregivers
  • clear and consistent family rules
  • good academic performance
  • school engagement and positive teacher experience
  • healthy peer groups
  • good social skills and ability to make friends.15-17

Connection as a pathway to recovery

Experiencing dependence can lead to isolation, social withdrawal and relationship issues.18,19

Social connection – feeling loved, like you belong, cared for and connected to others – reduces stress, boosts self-esteem, and improves mental and physical wellbeing.20

Social and human connection plays an important role in supporting people in their recovery and is one of the key pathways in AOD treatment.21

Recovery is different for everyone and can take many forms – from reducing harm or reducing use, to quitting completely.4 But, the endgame is the same: to help people reach their goals and full potential.

If you’re dealing with alcohol or drug use issues, or social isolation due to dependence or mental health issues – you’re not alone, help is available.

The support services below are a good first step in getting help.

  • Lifeline – 1300-11-14
  • Alcohol and Drug Information Service – 1800-250-015
  • Family Drug Support – 1300-386-186

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  1. Harvard Health. Understanding addiction - New insights into the cause of addiction. 2021 [2025 Apr 11]
  2. Australian Bureau of Statistics. National Study of Mental Health and Wellbeing 2020-2022. [2025 Apr 11]
  3. Health Direct. Substance abuse.  [2025 Apr 11]
  4. Pienaar K, Dilkes-Frayne E, Fraser S, Kokanovic R, Moore D, Treloar C, et al. Experiences of alcohol and other drug addiction, dependence or habit in Australia: Findings and recommendations from a national qualitative study. 2017. [2025 Apr 11]
  5. Sussman S, Sussman AN. Considering the Definition of Addiction. International Journal of Environmental Research and Public Health. 2011;8(10):4025-38. [2025 Apr 4]
  6. National Institute of Drug Abuse (NIDA). Understanding Drug Use and Addiction DrugFacts.  [2025 Apr 11]
  7. National Institute of Drug Abuse (NIDA). Drugs and the brain.  [2025 Apr 11]
  8. National Institute of Drug Abuse (NIDA). Addiction and Health.  [2025 Apr 11]
  9. National Institute of Drug Abuse (NIDA). The Science of Drug Use: A Resource for the Justice Sector.  [2025 Apr 11]
  10. National Institute of Drug Abuse (NIDA). Drug misuse and addiction.  [2025 Apr 11]
  11. Ritter A, King T, Hamilton M. Drug use in Australian society South Melbourne, Vic: Oxford University Press; 2017 [2025 Apr 11].
  12. Australian Institute of Health and Welfare. National Drug Strategy Household Survey 2022–2023 2024. [2025 Mar 7]
  13. Stone AL, Becker LG, Huber AM, Catalano RF. Review of risk and protective factors of substance use and problem use in emerging adulthood. Addictive Behaviors. 2012;37(7):747-75. [2025 Apr 11]
  14. Cleveland MJ, Feinberg ME, Bontempo DE, Greenberg MT. The Role of Risk and Protective Factors in Substance Use Across Adolescence. Journal of Adolescent Health. 2008;43(2):157-64. [2025 Apr 11]
  15. Nawi AM, Ismail R, Ibrahim F, Hassan MR, Manaf MRA, Amit N, et al. Risk and protective factors of drug abuse among adolescents: a systematic review. BMC Public Health. 2021;21(1). [2025 Apr 11]
  16. Hosseinbor M, Yassini Ardekani SM, Bakhshani S, Bakhshani S. Emotional and social loneliness in individuals with and without substance dependence disorder. Int J High Risk Behav Addict. 2014;3(3):e22688-e. [2025 Apr 11]
  17. Johnson BR, Pagano ME, Lee MT, Post SG. Alone on the Inside: The Impact of Social Isolation and Helping Others on AOD Use and Criminal Activity. Youth Soc. 2018;50(4):529-50. [2025 Apr 11]
  18. Wilkinson A, Bowen L, Gustavsson E, Håkansson S, Littleton N, McCormick J, et al. Maintenance and Development of Social Connection by People with Long-term Conditions: A Qualitative Study. International journal of environmental research and public health. 2019;16(11):1875. [2025 Apr 11]
  19. Pettersen H, Landheim A, Skeie I, Biong S, Brodahl M, Oute J, et al. How Social Relationships Influence Substance Use Disorder Recovery: A Collaborative Narrative Study. Substance abuse: research and treatment. 2019;13:1178221819833379-. [2025 Apr 11]

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