Using any sort of substance—alcohol, marijuana, cocaine, and so on—is inherently risky. These substances always come with the potential of addiction or dependency, or even substance use disorder.
That said, there are plenty of people who occasionally drink alcohol or dabble in marijuana products, but seem to have control over their usage. They can self-regulate their intake, stop before they’ve taken too much, and go days, weeks, or months without experimenting again.
“Certain folks, though, either from genetic predispositions or from having co-occurring mental health issues, [will] start using a substance, and then find it very hard to curb their use over time,” says Jonathan Avery, MD, director of Addiction Psychiatry at Weill Cornell Medicine and NewYork-Presbyterian Hospital.
Substance use disorder is a disease that leads to compulsive use of a substance despite impaired physical, mental, and social function. In other words, continued use of the substance is having harmful consequences, but you have a strong desire to continue use.
Of course, in reality, it’s harder to see where the line is between substance misuse and substance use disorder. Substance misuse simply refers to the harmful use of substances for non-medical purposes. There are plenty of ways people misuse substances: happy hours multiple times a week, occasional drug use, weekend hangovers, etc.
So when does it cross the line to a disorder?
“In general, the definition we look for is that when you're using a substance in a way that impairs your function over time, that's when we really think you're getting into trouble,” says Dr. Avery.
Someone with substance use disorder may have behavioral changes (mood swings, agitation, apathy, secretiveness), physical changes (weight gain or loss, tremors, bloodshot eyes), or social changes (change in friends and hobbies, financial problems, relational conflicts).
Additionally, Dr. Avery suggests two major signs of substance use disorder. “One is you find [that] substance use becoming the answer to every question in your life,” says Dr. Avery. Using a substance becomes the thing you do after work, when you’re bored, when you’re hungry, when you’re lonely, and when you’re happy.
The other sign requires listening to comments by loved ones. “It's often the loved ones that are the first ones that are aware of this and say, ‘Hey, what's going on here?’” says Dr. Avery.
Substance use disorder, like other mental health issues, can be treated. It may involve a combination of rehabilitation, medications, psychotherapy, and group therapy or support groups. (Find out what to expect at your first therapy session here.)
Substance Abuse and Mental Health Services Administration. (2023). Mental health and substance use disorders.
Torrise, B. (n.d.). Help with addiction and substance use disorders. American Psychiatric Association.
U.S. Department of Health and Human Services. (2023). Mental health and substance use disorders.
If you or someone you know struggles with substance use, help is available. Call SAMHSA’s National Helpline at 1-800-662-4357 to learn about resources in your area.