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Understanding Substance Use Disorders

Substance Use Disorders

A substance use disorder (SUD) is term to describe the disease of addiction. It is a chronic, relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences. It is considered a disease because drugs change the structure of the brain and how it works (1). The substances attach to receptors in the brain that are usually filled with a naturally-produced hormone called dopamine. When a person takes drugs, an abnormally high amount of dopamine is produced, causing euphoria (a really intense high). When someone continues to use drugs, their body no longer produces the amount of dopamine that is usually produced when doing things that make them feel happy such as exericsing, spending time with friends and family, or doing their favorite activity. 

Terms to Know

  • Physical Dependence is when a person becomes dependent on a substance due to long term exposure to a drug.
  • Addiction, which can include physical dependence, is distinguished by compulsive drug seeking and use despite sometimes devastating consequences.
  • Tolerance is the need to take higher doses of a medication to get the same effect. When tolerance occurs, it can be difficult for a physician to evaluate whether a patient is developing a drug problem, or has a real medical need for higher doses to control their symptoms. For this reason, physicians need to be vigilant and attentive to their patients’ symptoms and level of functioning to treat them appropriately.
  • Withdrawal is when a person who is physically dependent or addicted to a substance has stopped using or reduced the amount they are using and is experiencing symptoms such as muscle and bone pain, cold sweats, shaking, diarrhea and vommiting.
  • Prevention is delivered prior to the onset of a disorder, these interventions are intended to prevent or reduce the risk of developing a behavioral health problem, such as underage alcohol use, prescription drug misuse and abuse, and illicit drug use (2).
  • Treatment is when a person receives services to help them overcome and manage their SUD. There are a number of different roads that people can take to help treat a SUD and no one's journey to recovery will be the same. Each person needs to decide what is best option for them and how they can treat and recover from their SUD.
  • Recovery is when a person no longer uses substances. Recovery can be a difficult thing and people can experience one or multiple relapses (return to use of substances) during their recovery. These are bumps in the road and in no way mean that a person has failed. Relapses can be a part of a person's road to recovery and can be prevented and overcome.
  • Overdose is a medical emergency when a person has taken too much of a substance. Signs of an overdose include slowed or stopped breathing, drowziness or "nodding off", blue lips and fingernails, unresponsiveness. If you or someone you know is experiencing an overdose, call 911 immediately. There are laws that can protect you. People in early recovery don’t experience normal levels of reward, which makes them much more susceptible to relapsing in those first 6-9 months. During this time period, people who relapse have a higher risk of overdosing because of a lowered tolerance. For more information on overdoses, or responding and preventing them, click here
  • Opioids are a class of drugs that include heroin, fentanyl, percosets, oxycodone, OxyContin, hydrocodone and other prescription painkillers.


Please watch this informative video on the subject: