Library · Disease
Substance use disorder
Make it clearer
Substance use disorder affects the brain and behavior, and it shows up in daily life: it causes problems at work, at school or in relationships.
To understand it, you have to look at the reward circuit, a network of neurons that pushes us to repeat what feels good. Most drugs flood that circuit with dopamine, a chemical messenger between neurons. Those surges reinforce the behavior of using, and that is how they lead people to repeat it.
If use continues, the brain adapts and the cells in that circuit respond less. Tolerance may then develop, which means needing more of the substance to feel the same effect. It is like ears that have gotten used to noise: to hear the same thing, you have to turn up the volume. And when the substance is stopped, withdrawal symptoms may appear, the discomfort that sets in when it is missing.
In brief
Substance use disorder affects the brain and behavior, causing problems at work, at school or in relationships.
Most drugs flood the reward circuit with dopamine; these surges reinforce the behavior of using and lead people to repeat it.
If use continues, the brain adapts and that circuit responds less; tolerance may develop, meaning more of the substance is needed for the same effect, or withdrawal may appear when it is stopped.
Like ears used to noise: to hear the same, you have to turn up the volume.
Sources (2)
- National Institute of Mental Health, National Institutes of HealthFinding Help for Co-Occurring Substance Use and Mental Disorders, NIMHPublished
- National Institute on Drug Abuse, National Institutes of HealthUnderstanding Drug Use and Addiction DrugFacts, NIDAPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated