Addiction and Mental Health

Drugs and alcohol are substances that can alter brain chemistry, therefore influencing how an individual might think and behave. Whilst occasional use of alcohol or drugs can help people relax and enjoy themselves, long term use of drugs that have not been prescribed by a doctor, is linked to a range of mental and physical health problems. 

Types of drugs

Common types of drugs include:


Increase the activity of the central nervous system and cause the user to feel energetic and euphoric.

  • Eg. Cocaine, caffeine, methamphetamine


Alters how an individual perceives the world by changing their sensations. 

  • Eg. Psilocybin (magic mushrooms), LSD


Reduce activity in the central nervous system and create a sedative feeling

  • Eg. Alcohol, cannabis, opioids


Painkillers that can produce a sense of euphoria

  • Eg. Heroin, morphine, codeine

Effects on mental health and functioning

Unhealthy drug and alcohol use often co-occurs with the presentation of mental health issues. This is because these substances may be used to cope with uncomfortable feelings, however they can also worsen mental health issues at the same time.

Sustained drug and alcohol use can limit the brain’s ability to feel pleasure. An individual may become desensitised to other pleasurable activities and crave higher doses of a substance to feel the same high. This can often cause a cycle of dependence and affect an individual’s ability to function in daily life.

Disruptions to daily functioning may include relationship issues or an impaired ability to efficiently perform daily tasks. Furthermore, time that might otherwise have been spent with others or working on oneself can be consumed by an addiction. This may contribute to social isolation or a lack of self care, which can worsen mental health issues. Addiction to a substance can disrupt the normal rhythms of our life by disrupting our sleeping and eating habits, which can also place stress on the body.

Drug/Alcohol withdrawal

Withdrawal refers to the period of when the body no longer has access to a substance it is dependent on.

Withdrawal experiences may differ depending on the individual, the drug, and their level of dependence on a substance.

However symptoms of withdrawal can include:

  • Headaches
  • Insomnia
  • Nausea
  • Feelings of anxiety, stress, depression or anger

With more severe symptoms including: 

  • Confusion
  • Fever
  • Delirium

As the brain re-adapts to functioning without the effects of alcohol or drugs, these symptoms will fade. However during this period, self-care, eating healthy foods and the support and company of friends or family is important.

If your symptoms are severe, seek help from a medical professional.

Taking action to change habits

Changing alcohol and drug habits can be hard and takes commitment and time, however the positive effects of reducing use on both the body and mind make it worth the effort. The process of addressing drug and alcohol habits can be difficult and many people experience setbacks. It is important to realise that this is normal and to be kind to yourself as changing habits takes time and it’s normal to experience setbacks.

Seeing a healthcare professional or counsellor may also be worthwhile, as they can assist you through this process. Having a strong support network around you is also beneficial for recovery. If a drug or alcohol problem is a product of a mental illness, the mental illness may need to be addressed as well in order to make a full recovery.