What are Substance Use Disorders (SUD)?

We're here to help you or your loved one.

Substance use disorders (SUD) occur when someone's use of a substance (drug or alcohol) causes health problems or problems at work, school, or home. A common sign of a SUD is when someone is unable to stop using a substance despite adverse consequences. Commonly associated terms include substance abuse, drug abuse, drug use disorder, and drug addiction.

Drugs from the following eleven categories are the source of most substance-related disorders:

Substance Use Disorders and Mental Health

Substance use disorders are progressive, chronic, relapsing, and treatable diseases. They alter the way your brain functions, resulting in changed behaviors, priorities, and the ability to work, go to school, and maintain healthy relationships.

It is common for people with mental health disorders to develop substance use disorders, and vice versa. If someone is diagnosed with a substance use disorder and mental disorder at the same time, they have a co-occurring disorder, also known as a dual diagnosis.

COVID-19 Doesn’t Have to Stop You From Getting Help

Rehab facilities are open and accepting new patients

Substance Use Disorder DSM 5 Definition

The DSM 5 states that for someone to be diagnosed with a substance use disorder, they must meet at least two of the following criteria:

  • Taking larger amounts of the substance or using it longer than you should
  • Unable to cut down or stop using the substance
  • Spending excess time obtaining, using, or recovering from substance use
  • Cravings and urges to use
  • Unable to meet work, home, or school responsibilities because of substance use
  • Continuing to use the substance, even when it causes relationship problems
  • Giving up social, occupational, or recreational activities in favor of substance use
  • Using substances regardless of danger
  • Realizing you have a physical or psychological problem caused or made worse by the substance and continuing to use it
  • Developing a tolerance (needing more of the substance to get the effect you want)
  • Having withdrawal symptoms, which go away when you take more of the substance

SUDs get categorized in terms of their severity. If a patient exhibits two or three of the criteria, they have a "mild" substance use disorder. Four or five means they have a "moderate" substance use disorder, while six or more makes it a "severe" diagnosis.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, referred to as the DSM-V or DSM 5, is the American Psychiatric Association’s current manual for assessing and diagnosing mental disorders. It is the gold-standard text of the diagnostic criteria for all mental health issues in the United States.

Types of Substance Use Disorders

A person’s SUD diagnosis depends on the type of substance that they misuse. If someone misuses multiple types of substances, this is known as “polysubstance use disorder."

The most common types of substance use disorders include:

Alcohol Use Disorder

Alcohol is one of the most commonly consumed substances in the world. It’s legal almost everywhere and very easy to obtain. The three main categories of alcohol problems are binge drinking, alcohol abuse, and alcohol dependence (alcoholism).

Tobacco Use Disorder

Nearly 500,000 deaths each year make cigarette smoking the number one cause of preventable death in the United States. Over 30 million people are current smokers.

Marijuana Use Disorder

Marijuana is the third most used substance in the United States, after alcohol and tobacco. According to the National Institute on Drug Abuse (NIDA), Marijuana use disorder is similar to other substance use disorders. However, the long-term effects may be less severe.

Opioid Use Disorder

Opioids are pain relievers that are generally safe when taken as prescribed by a doctor for a short period. However, they also produce a euphoric high, which makes people misuse and abuse them frequently. Opioid misuse can lead to dependency, addiction, overdose, and even death. Common opioids include hydrocodone (Vicodin), oxycodone (OxyContin and Percocet), oxymorphone (Opana), morphine (Kadian, Avinza), codeine, and fentanyl.

Stimulant Use Disorder

Stimulants are a class of drugs that increase alertness and energy, as well as blood pressure, heart rate, and breathing. They include illicit drugs such as cocaine and methamphetamine, as well as prescription drugs like Adderall and Ritalin. Prolonged use of stimulants can have significant negative effects, including heart damage, memory loss, and psychotic behavior.

Sedative Use Disorder

Sedatives are central nervous system (CNS) depressants that slow brain activity. They are used to treat anxiety and sleep disorders. However, they are also abused frequently. Tolerance and dependence can develop quickly when someone misuses or abuses sedatives. Examples of common sedatives include alprazolam (Xanax), lorazepam (Ativan), diazepam (Valium), and zolpidem (Ambien).

Hallucinogen Use Disorder

Hallucinogens are either synthetically produced, like LSD, or occur naturally, like shrooms and peyote. They produce visual and auditory hallucinations, feelings of detachment from one's self and environment, and a distorted perception of time and space. Most hallucinogens do not cause physical addiction. However, users may develop a psychological dependence. They may also develop hallucinogen persisting perception disorder (HPPD), which is spontaneous, recurring flashbacks.

Causes of Substance Use Disorders

The causes of SUDs and addiction are only partially understood by researchers. Typically, users progress from occasional to heavy substance use and then proceed to develop a substance use disorder. This progression is very complex and depends on the interaction between the person, setting, and drug.


Different people have different risk factors for developing a SUD. Both genetics and environment play a role in the likelihood of someone misusing or abusing drugs.

People whose families have a history of addiction or mental health disorders are more likely to develop one themselves. People who live in high-risk environments, such as lower-income families, the LGBTQ+ community, and people without access to healthcare are also more at risk.

Anyone can develop a substance use disorder, regardless of their background. However, certain types of people are more susceptible, such as:

  • People with mental disorders
  • Individuals who experience social isolation
  • Anyone who has undergone trauma
  • People with chronic pain

A person's environment can play a huge role in drug use. Family, peers, and even doctors can contribute to someone's substance use.

Certain environments are more conducive to drug abuse. For example, someone who grows up watching a family member struggle with addiction, or whose entire friend group starts doing drugs, has a higher chance of developing a SUD.


Drugs are categorized by how likely they are to cause use disorders or addiction. This is also known as assessment of abuse, potential of drugs, abuse liability, or addiction liability. This liability depends on:

  • How the drug is used
  • How strongly the brain’s reward pathway is stimulated
  • How quickly the drug takes effect
  • How quickly tolerance and withdrawal symptoms develop

People tend to use drugs that are legal, or easier to obtain, such as tobacco, alcohol, and marijuana, first. These can cause addiction, or make people feel comfortable with drug use, leading them to try stronger or illegal drugs.

Symptoms of Substance Use Disorders

Symptoms of drug abuse and addiction include, among others:

  • Feeling that you need to use the drug daily or several times a day
  • Intense urges for the drug
  • Needing more of the drug to get the same effect
  • Taking larger amounts of the drug or using for a longer period of time than intended
  • Ensuring you have a constant supply of the drug
  • Spending too much money on the drug, even if you can't afford it
  • Not meeting social or work responsibilities, or cutting back on recreational activities due to drug use
  • Continuing to use the drug regardless of it causing problems in your life or physical or mental harm
  • Doing things you normally wouldn't do, like stealing, to get the drug
  • Engaging in risky activities such as driving when you're under the influence of the drug
  • Spending too much time getting, using, or recovering from the drug
  • Failed attempts to cut back or stop using the drug
  • Getting withdrawal symptoms when you stop taking the drug
Recognizing signs of drug use or intoxication

The signs of drug use will vary by the type of drug, but some of the most common signs that someone is intoxicated include:

  • Red eyes
  • Dilated pupils
  • Poor judgment
  • Decreased coordination
  • Slowed reaction time
  • Drowsiness
  • Difficulty concentrating or remembering
  • Anxiety or paranoid thinking
  • Agitation or mood swings
  • Behavior changes
Recognizing unhealthy substance use in friends or family members

Some of the most common signs of unhealthy substance use include:

  • Problems at school or work — being absent, or developing a sudden disinterest in activities at school or work, or a decrease in grades or work performance
  • Health issues — loss of energy and motivation, fluctuations in weight, increased blood pressure, mouth sores, and tooth decay
  • Neglected appearance — neglecting showering, grooming, or caring about their clothes
  • Changes in behavior — increased secrecy, changes in morals, lying, changes in friend groups, and dropping activities that they used to enjoy
  • Money issues — borrowing or stealing money, complaining about not having enough money when they did before

It’s important to note that not everyone showing these symptoms has a substance use disorder. Many mental health disorders, such as depression and anxiety disorders, will cause people to act these ways as well. It’s also possible that someone is going through a rough patch, or has just had a negative reaction to something, and will recover on their own.

Substance Use Disorder Treatment Options

Some common treatments for substance use disorder include:

What's best for one person may not be best for someone else. There are also several factors that will determine what type of treatment program is best, including:

  • Type of substance use disorder
  • The severity of your disorder
  • Work, familial, or school responsibilities
  • Living situation
  • Existing support system
  • Financial situation

If you or someone you know is displaying symptoms of a substance use disorder, the best thing to do is to start doing research and talk to a healthcare professional.

Find Help For Your Addiction

You don’t have to overcome your addiction alone. Professional guidance and support is available. Begin a life of recovery by reaching out to a specialist today.

Resources +

McLellan, A Thomas. “Substance Misuse and Substance use Disorders: Why do they Matter in Healthcare?.” Transactions of the American Clinical and Climatological Association vol. 128 (2017): 112-130, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525418/

NIDA. "Common Comorbidities with Substance Use Disorders." National Institute on Drug Abuse, 1 Apr. 2020, https://www.drugabuse.gov/publications/research-reports/common-comorbidities-substance-use-disorders.

SAMHSA. "Mental Health and Substance Use Disorders." Substance Abuse and Mental Health Services Administration, 13 Apr. 2019, www.samhsa.gov/find-help/disorders.

Agrawal, Arpana, et al. "DSM-IV to DSM-5: the impact of proposed revisions on diagnosis of alcohol use disorders." Addiction, vol. 106, no. 11, 2011, pp. 1935-1943, https://pubmed.ncbi.nlm.nih.gov/21631621/

"NIMH » Substance Use and Mental Health." National Institute of Mental Health, May 2016, www.nimh.nih.gov/health/topics/substance-use-and-mental-health/index.shtml.

Round cornerRound corner
addiction group logo
ag logo

Find Treatment Today

Are you struggling with substance abuse? You aren’t alone. Here are some of the most frequently asked questions about addiction and treatment:
What is the difference between physical dependence and addiction?How effective is addiction treatment?How long is addiction rehab?
Depending on your unique situation, there are many addiction treatment options available. Compare the most effective types of treatment options here:
Inpatient RehabPartial Hospitalization ProgramsOutpatient Rehab
addiction group logo
All unique content created by the Addiction Group team is sourced from current scientific research and fact-checked by an addiction counseling expert before publication. However, the information provided by Addiction Group is not a substitute for professional treatment advice. Read more in out About Us.

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

© 2021 by TREATMENT PATHWAY, LLC. All right reserved.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram