Medically reviewed by Peter Kassis, MD, FASAM on August 25, 2026.
Opioid use disorder (OUD) is a treatable medical condition linked to changes in how the brain responds to opioids. This page explains what OUD means, how it’s diagnosed, what withdrawal involves, and how care can support steadier days. At Health Care Resource Centers, you’ll get respectful, evidence-based guidance and clear next steps.
OUD is a chronic condition linked to changes in brain chemistry. Over time, opioids affect the parts of the brain that control reward, stress, and decision-making, and you may feel unable to stop using without physical or emotional distress. It affects people of all ages, backgrounds, and circumstances. OUD can involve:
Many illicit opioids now contain fentanyl, a highly potent synthetic opioid that increases overdose risk, often without the person knowing it’s there.
OUD is diagnosed by a clinician using eleven criteria set out in the DSM-5-TR, the diagnostic manual published by the American Psychiatric Association. Meeting two or more within a twelve-month period supports a diagnosis.
The criteria look at whether you:
Take opioids in larger amounts, or for longer, than you intended
Want to cut down or stop and haven’t been able to
Spend significant time getting opioids, using them, or recovering from them
Experience cravings or strong urges to use
Find opioid use interfering with work, school, or responsibilities at home
Keep using despite problems it causes with the people around you
Have given up activities that used to matter to you
Use in situations where doing so is physically hazardous
Keep using despite a physical or mental health problem opioids are making worse
Have developed tolerance, needing more for the same effect
Experience withdrawal when opioids wear off
Clinicians describe OUD as mild when two or three criteria are present, moderate at four or five, and severe at six or more. If you take opioids exactly as prescribed under medical supervision, tolerance and withdrawal on their own don’t indicate opioid use disorder.
You don’t need a diagnosis before contacting us. An assessment is part of getting started.
Signs and symptoms look different for each person. Some show up in your body, others affect your routines, mood, and choices. You may notice:
If these feel familiar, it can help to talk with a provider. A clear assessment is the first step toward a plan that supports stability.
Withdrawal is one of the main reasons people find it so hard to stop on their own.
For short-acting opioids such as heroin, oxycodone, or fentanyl, symptoms usually begin six to twelve hours after the last dose. For long-acting opioids such as methadone, onset is slower, often twenty-four to forty-eight hours. Symptoms typically peak within the first one to three days, and the acute phase generally eases over five to ten days.
Common withdrawal symptoms include:
Some symptoms, particularly poor sleep, low mood, and cravings, can linger for weeks or months after the acute phase. This is sometimes called protracted withdrawal, and it’s a common reason people return to use.
Medication-assisted treatment isn’t a way of getting through withdrawal and then stopping. Methadone and buprenorphine prevent withdrawal from happening in the first place, which is why they support stability over the long term.
Opioids attach to receptors in the brain that control pain, reward, and stress. At first they may reduce pain or create a sense of relief. With repeated use, the brain adjusts and begins to function differently, coming to rely on opioids to feel normal. Tolerance increases, meaning more is needed for the same effect, and stopping suddenly causes withdrawal. These changes are why OUD is treated as a medical condition that responds best to structured care.
People often ask, “Is OUD a chronic disease?” Opioid use disorder is considered a chronic, relapsing condition, similar to diabetes or asthma. Symptoms can return without ongoing care. Long-term treatment helps reduce cravings and withdrawal, lower overdose risk, support steady routines, and improve overall health.
The risk profile has changed. Fentanyl now appears throughout the illicit supply, including in pills sold as prescription medication and in powders sold as something else entirely. There’s no reliable way to identify it by sight or taste.
Two situations raise risk further. Combining opioids with benzodiazepines, alcohol, or stimulants makes overdose more likely and harder to reverse. And after any break in use, whether a hospital stay, time in custody, or simply a few days without opioids, tolerance drops quickly. Returning to a previous amount after that break is one of the most dangerous moments in the whole condition.
Staying in MAT is associated with substantially lower rates of overdose death compared with no treatment. It doesn’t remove risk, which is why keeping naloxone available remains sensible for anyone using opioids and the people around them.
The most effective treatment combines medication with supportive care, an approach often called Medication-Assisted Treatment (MAT), or MOUD, meaning medications for opioid use disorder.
With treatment, you’ll receive medication to stabilize withdrawal and cravings, individual counseling to build coping skills, case management support for practical needs, and ongoing medical monitoring.
Treatment is outpatient, so it fits around work and family. Early on you’ll visit the clinic daily for medication. As you stabilize, take-home doses may be earned based on your progress and program guidelines. For people carrying past trauma alongside substance use, trauma-informed care addresses both together.
Several FDA-approved medications are used in OUD treatment. Each works differently, and your provider helps determine which fits your situation.
Learn more about methadone treatment.
Learn more about buprenorphine and Suboxone treatment.
The choice depends on your history, how much structure is helpful for you, whether you’re pregnant, what other medications you take, and what you want from treatment. Neither medication is a lesser option, many people do well on either, and it’s possible to change if the first choice isn’t working.
Medication doesn’t replace one problem with another. It restores enough balance for the rest of recovery to become possible. If you take other prescriptions, our guide to MAT guidelines and drug interactions explains what to tell your care team.
Recovery is personal, and progress usually happens in stages.
Induction. Finding a safe starting dose and getting stable.
Stabilization. Fewer cravings and better day-to-day functioning.
Maintenance. Long-term support while you rebuild the rest of your life.
Taper. Gradual changes, if and when that’s right for you.
Any decisions are made with your care team, based on safety and readiness rather than a set timeline.
Starting treatment begins with one conversation. You’ll get a respectful assessment, clear guidance, and a plan built around your needs and goals.
At Health Care Resource Centers, you can begin evidence-based OUD treatment with medication, counseling, and practical support in a structured outpatient setting at our Lewiston and Portland, Maine centers.
Find a location near you, or contact us to schedule an assessment. If you’re in immediate danger, call 911. For crisis support, call or text 988.
OUD stands for opioid use disorder, a medical condition involving changes in the brain related to opioid use.
A clinician assesses you against eleven DSM-5-TR criteria. Meeting two or more within twelve months supports a diagnosis, and the number met determines whether it’s mild, moderate, or severe.
Dependence means the body has adapted to a substance, so stopping causes withdrawal. It can happen to anyone taking opioids as prescribed. Opioid use disorder is broader and includes loss of control, cravings, and continued use despite harm.
The acute phase usually lasts five to ten days, beginning six to twelve hours after the last short-acting opioid. Sleep problems, low mood, and cravings can continue for weeks or months afterward.
Counseling on its own helps some people, but the evidence consistently shows that combining medication with counseling produces better outcomes than counseling alone, including lower overdose risk. Your provider can talk through what fits your situation.
Yes. OUD is treatable with medication, counseling, and long-term support tailored to your needs.
The MOUD meaning is medications for opioid use disorder. It includes methadone and buprenorphine, used alongside counseling.
There’s no set timeline. Length depends on your stability, your goals, and medical guidance.
Yes. Medication-Assisted Treatment is associated with substantially lower overdose risk than continued opioid use without treatment.
Often quickly. Contact us and we’ll explain the next available assessment at the center closest to you.
For more questions, see our frequently asked questions or contact us.
