Addiction is the most severe form of substance use disorder (SUD). It is complex, focusing on using certain substances such as alcohol or illicit drugs that make it difficult for the addicted person to function in their day-to-day life. Even though the use of the substance is causing them problems, they continue to use it.

The person with SUD may have distorted thinking and behaviors. Brain imaging studies have shown changes in areas in the brain related to judgment, decision making, behavior control, and memory. Some structural changes in the brain are responsible for the intense craving the person experiences.

The changes made in the brain of someone repeatedly using a substance can last long after the substance is out of their system. Eventually, they will also build up a tolerance to the substance and need more significant amounts to feel its effects.


There are many reasons why people might want to use intoxicating and potentially addictive substances.

It often begins with experimentation. They are curious and want to try what their friends are doing. Peer pressure.

Escapism is another reason. They want to feel pleasure or even numb. It is a way of relieving stress and forgetting their problems temporarily.

Performance enhancement can turn a quick fix into a long-term problem when the fix is an addictive substance.

Prescribed a pain pill to no fault of their own for a legitimate reason, and now have an addiction to pain pills.

Family history of addiction, social norm, learned behaviors

Self-help for underlying stressors or mental health

To get off another addictive substance

To escape emotional or physical pain

To self-treat depression or anxiety

To attempt to help with sleeping issues

Social enjoyment

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