Understanding the signs and causes of substance misuse

girl against a wall

When you think about substance misuse, certain types of substances (or people) might naturally come to mind. But it’s important to remember that substance misuse can involve people of all ages, from all walks of life, and that the drugs, drinks and other substances that people misuse may take a range of different forms.

While alcohol and drugs such as cannabis, cocaine and heroin are among the most common substances that people misuse, activities such as smoking cigarettes, taking steroids, or even drinking too much coffee are also considered to be substance misuse.   

Substance misuse is a complex issue. That’s why whether you’re a parent, a health professional or a young person who is involved with drugs on a personal or professional capacity, it’s quite reasonable to find yourself asking ‘what is substance misuse?’. By knowing exactly what substance misuse is, you’ll then be able to make an informed judgement about whether you or someone you know is abusing or misusing substances.

Defining substance misuse

Substance misuse can be commonly defined as:

‘A patterned use of a drug in which the user consumes the substance in amounts or with methods which are harmful to themselves or others, and is a form of substance related disorder.’ 

This is the definition the NHS uses, and it’s worth highlighting a couple of words used within the above definition that may help you recognise whether someone is misusing substances or not.


The first thing to note is the use of the phrase ‘patterned use’, which would mean that a person who infrequently or irregularly misuses substances wouldn’t technically be defined as a substance misuser. 

Obviously this is a little misleading, as someone who excessively uses substances even occasionally is taking a number of serious risks. 

However, if you notice a degree of regularity in your (or others’) behaviour – for example regular hangovers on a Friday, or frequently drug taking on weekends – then it’s likely they may be misusing substances.

Health risks 

The other element of the NHS’s definition worth paying particular attention to is the description of ‘harmful to themselves or others’. Drug misuse is without exception damaging to a person’s physical health. Depending on the substance being used there are risks of a person:

  • contracting infectious diseases such as HIV or hepatitis 
  • damaging key organs such as their heart, liver and kidneys
  • affecting their hormone levels 
  • increasing their risk of cancer 

And substance misuse is also damaging to a person’s mental health – it can cause both short and long term changes to the brain which in turn can lead to issues including depression, anger, anxiety and paranoia.    

It’s worth noting that substance misuse a different thing from substance dependency, which is when someone is physically or mentally addicted to something. People who misuse substances can often to this without being addicted to the substance in question.

Commonly misused substances

The types of harmful substances people might misuse include:

  • Alcohol
  • Amphetamines 
  • Butane
  • Cannabis
  • Cocaine
  • Ecstasy
  • Heroin 
  • Ketamine
  • Khat
  • LSD
  • Magic Mushrooms
  • Prescription drugs (such as sleeping pills and painkillers)
  • Steroids
  • Tobacco 

Potential causes of substance misuse

While any person of any age from any background can be affected by substance and drug misuse, there are certain experiences and scenarios that can make a person more prone to misusing or abusing substances.

These include a person having:

  • Been neglected or had a traumatic experience – often this person will use substances to try and numb the pain their experiences have caused them.
  • Experienced peer pressure to consume and abuse substances – friends or colleagues may encourage people to take substances, and make them feel like their behaviour is harmless or normal. 
  • Had mental health issues, or have a history of mental illness – this could apply to a person’s family members too, as it may result in an inherited predisposition to addiction or abuse. 

What to do if you're worried about substance misuse

If you think you or someone you know might be having a problem with substance misuse find the contact details for your local substance misuse service.

Further information

There are also several other organisations you can contact for support: