Understanding the Effects of Substance Misuse

Drug abuse and alcohol addiction can affect different people in different ways.

The ways in which substance abuse can affect you varies depending on the substance that has been abused, the level of abuse and the way in which the substance was administered – for example, snorted, injected, or ingested.

Even one single occasion of abusing drugs or alcohol can lead to negative consequences for the user or those around them.

Long-term abuse of drugs and/or alcohol can cause many negative effects – some of which could be life-changing or irreversible.

Substance abuse can have a serious negative impact on your mental and physical health as well as your social and work life.

If you or someone you know is suffering from substance misuse and is considering seeking help, it is helpful to know what signs and symptoms to look out for.

A person suffering from substance misuse might experience some or all of the following side effects, however, this is not an exhaustive list and seeking professional help is the best way to ensure that the right treatment is given.

Physical side effects

Some physical side effects of substance misuse are:

Mental side effects

Some mental side effects of substance misuse are:

  • Memory loss
  • Poor concentration
  • Lack of focus
  • Irritability
  • Intense cravings for whichever substance they prefer
  • Disorientation or confusion
  • Continuously making bad decisions

Some effects of substance misuse can occur immediately after taking certain substances such as effects on heart rate or blood pressure, psychotic episodes or overdoses that can result in coma or even death.

Poor decision-making abilities linked to substance misuse can also lead to risky behaviour such as unprotected sex, driving under the influence or sharing needles.

Other short-term side effects of substance misuse include:

  • Rapid increase or decrease of appetite
  • Slurred speech
  • Problems with co-ordination
  • Insomnia or waking regularly throughout the night

As substance misuse can also affect your personal life, someone dealing with substance misuse may also notice other side effects such as:

  • Relationship troubles
  • Loss of friendships
  • Issues at work or school
  • Lack of interest in hobbies they once enjoyed
  • Legal troubles
  • Money troubles
  • Issues maintaining personal hygiene

While short-term side effects tend to disappear or get better once you stop using the substance that caused the side effects, there are also many side effects from substances that can be long-term or even permanent.

Long-term side effects of substance misuse include:

As substance misuse can alter a person’s brain chemicals, other long-term side effects include issues with learning or retaining new information, poor judgement and decision making, behavioural issues and prolonged stress.

Substance misuse is a damaging and often life-threatening illness that shows itself in many different ways. The mental and physical symptoms are only the beginning of how they can affect your entire life.

As the cravings for the substance increase, the user will also need larger doses to get the desired effect which leads to stronger cravings and a more dangerous addiction that can be more difficult to overcome.

As the addiction worsens, the user can withdraw from friends or family members in order to hide their addiction, and associate with other people who suffer from the same substance misuse. This can lead to job loss, disruption to education or the breakdown of relationships.

All of these things can exacerbate the addiction and it becomes a vicious cycle.

Why do some people develop addictions while others don’t?

There is no one particular factor that makes people more likely to develop an addiction. There are, however, a number of risk factors that can make a person more susceptible to addiction.

Some of these risk factors are:

1. Biology

Studies have shown that there are biological factors that contribute to addictive behaviours including race, culture, ethnicity, and the presence of other mental disorders (1).

2. Environment

A person’s environment can influence their actions. Someone who grows up around adults who regularly abuse drugs and alcohol are more likely to develop issues with substance misuse themselves. Other environmental factors such as sexual or physical abuse and peer pressure also contribute to substance misuse.

3. Development

Someone who begins to experiment with drugs and alcohol at a younger age is more likely to develop a problematic addiction (2) which will be more difficult to treat and can continue into adulthood.

Is there a cure for substance misuse?

While there is no cure for substance misuse, there is a range of treatments available to help you overcome your addiction. These include cognitive behavioural therapy, family therapy, peer support groups, detox, and rehab to name a few.

People overcoming addiction are at risk of relapse – sometimes for the rest of their lives. This is why continuing with peer support groups or therapy long after your addiction has ended is a good idea.

Breaking the cycle of substance misuse

While it may be difficult to admit that you have a problem, being honest with yourself about your substance misuse is the first step to overcoming your addiction.

Having an open and honest conversation with your closest friends or family members is also a good idea so that you have some support throughout your journey towards a substance-free life.

Visiting your healthcare provider and being honest with them about your substance misuse will get the ball rolling on your treatment.

They will be able to advise you on what treatment options are available and prescribe you any medication you might need.

They can recommend inpatient or outpatient treatment facilities as well as refer you for therapy such as family therapy or cognitive behavioural therapy to help you deal with invasive or negative thoughts and behaviours.

No matter how you decide to overcome your addiction, know that help is available, and you do not need to face the journey alone.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3935152/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827336/