Understanding Addiction: What Is Opioid Use Disorder?

In 2020, an estimated 2.7 million people in the United States suffered from opioid use disorder, according to the National Institute on Drug Abuse (NIDA). While this is a smaller number than for other substance use disorders — 28.9 million U.S. adults above age 12 live with alcohol use disorder according to the 2023 National Survey on Drug Use and Health (NSDUH) — the opioid crisis is one of the primary concerns among medical professionals and public health experts.

“In the world of addiction, we think of opioid use disorder on one hand, and all other substance abuse on the other hand,” says Jonathan Avery, MD, director of Addiction Psychiatry at Weill Cornell Medicine and NewYork-Presbyterian Hospital. “The reason we make that distinction is the deaths.”

The severity of opioid use disorder

Heavy use of substances like alcohol and cigarettes cause millions of deaths around the world each year. However, these deaths are often from related causes, such as cirrhosis, cancer, or COPD. These are problems that develop over time, which means there are more opportunities for intervention to decrease someone’s risk of death.

Opioids, on the other hand, can have fast and fatal effects. “The real scare about prescribing opioids for pain, or for people that get stuck on opioids, or experimenting with substances on the street, is that they'll have an accidental overdose, and they'll die,” says Dr. Avery.

Opioids affect a region of the brain that regulates breathing, so if taken in too high of amounts, opioids can lead to something called respiratory depression, or severely slow and shallow breathing. This is what leads to fatal opioid overdoses, which on average takes the lives of 128 people in the U.S. daily, according to NIDA.

Defining OUD

Opioid use disorder is not simply using opioids. Taking prescribed opioids for the recommended duration — such as to relieve pain after a major surgery — can be safe and effective without causing addiction.

“Opioid use disorder is when you're using opioids in a way that impairs your function,” says Dr. Avery, “and this can happen quick with opioids because they're a very difficult molecule to stop using once you take it.”

Why opioids are so addictive

Like many addictive substances, opioids cause effects in the reward center of the brain, leading to a “high” with feelings of ease and elation. Over time, the body can develop a physical dependence on the drug, and the body experiences unpleasant withdrawal symptoms without more opioids.

“The physical pull of opioids then leads to all these functional impairments in your personal life, family life, work life, and then you end up with an opioid use disorder,” says Dr. Avery.

Symptoms of OUD

You may have an opioid use disorder if you are experiencing:

• Uncontrollable cravings

• Drowsiness

• Weight loss

• Changes in hobbies, interests, and habits

• Isolation from loved ones

While the opioid crisis is a major concern, there’s reason to be hopeful: “There [are] more people in recovery in the United States than with active substance use disorder,” says Dr. Avery.

“When you're in the middle of [a] substance use disorder, it can feel hopeless at times, [and] it can feel like it's something you want to hide, but it's my experience once you get it out in the open, once you involve family, once you get the right treatment, that outcomes can be very positive,” says Dr. Avery.