Addiction can be described as a chronic disorder with various biological, psychological, social, and environmental factors that can influence its development and maintenance. Addictions vary from individual to individual, and approximately half of the risk for addiction is genetic. A person’s genes affect the degree of reward that individuals experience when initially using a substance like drugs or engaging in certain behaviours like gambling and the way the body processes alcohol or other drugs.

A desire to re-experience the use of the substance or behaviour can potentially lead to regular use or indulging in said substance or activity. These can be influenced by psychological, social, or environmental factors, and chronic use or indulgence can lead to brain changes. In terms of brain changes, these include alterations in cortical and subcortical regions of the brain that are the neuro-circuitry of reward, motivation, memory, impulse control, and judgment. When this happens, it can lead to an increase in cravings for a drug or activity and impairments in the ability to successfully regulate this impulse, despite knowing and experiencing the consequences of this addictive behaviour.