Addiction is when someone is unable to stop using a substance or doing something, to the point where it could be harmful. Addiction is most commonly associated with drugs, alcohol, smoking tobacco and gambling.
There are many causes of addiction. Drugs, alcohol and nicotine affect the way people feel, both physically and mentally. These feelings can be enjoyable and create a powerful urge to use the substance again. Addiction can start with experimental or occasional use in social situations, and become more frequent over time.
The risk of addiction and how quickly addiction develops depends on the drug. Some recreational drugs have a higher risk and cause addiction more quickly than others.
Having an addiction can be emotionally and physically damaging. Addictions often have a negative effect on health. For example, smoking tobacco can cause lung disease and increase the risk of many types of cancer. Long-term alcohol misuse can damage the brain and nervous system, heart, liver and pancreas.
NIHR-funded research increases our understanding of how to prevent and address smoking and addictions. You can learn more about this research below.