Substance Use Disorder: Spectrum, Diagnosis, and Treatment

What is a substance use disorder?

A substance use disorder (SUD) is a medical condition in which repeated use of alcohol or another drug leads to clinically significant impairment — problems with health, functioning, and control over use — that persists despite harm. It is understood as a treatable, often chronic disorder that changes brain circuits involved in reward, stress, and self-control; people can and do recover, and relapse, when it happens, is treated as part of the recovery process rather than a failure 6Ref 6National Institute on Drug Abuse (NIDA) (2025).Treatment (Research Topics).Methadone, buprenorphine, or naltrexone is the standard of care for opioid use disorder; behavioral therapies include CBT, contingency management, and motivational enhancement/interviewing; SUDs are chronic, treatable disorders and relapse is often part of the recovery process.

Substance use disorders are common. In 2023, an estimated 48.5 million people in the United States aged 12 or older — about 17.1% of that population — met criteria for a substance use disorder in the past year 1Ref 1Substance Abuse and Mental Health Services Administration (SAMHSA) (2024).Results from the 2023 National Survey on Drug Use and Health (NSDUH).In 2023, 48.5 million people aged 12+ (17.1%) had a past-year substance use disorder; 8.9 million misused opioids; of those needing treatment, 15.6% (7.1M) received it. Around 8.9 million people aged 12 or older misused opioids in the same period 1Ref 1Substance Abuse and Mental Health Services Administration (SAMHSA) (2024).Results from the 2023 National Survey on Drug Use and Health (NSDUH).In 2023, 48.5 million people aged 12+ (17.1%) had a past-year substance use disorder; 8.9 million misused opioids; of those needing treatment, 15.6% (7.1M) received it.

The DSM-5 replaced the older split between "substance abuse" and "substance dependence" with a single substance use disorder diagnosis measured on a continuum from mild to severe. The revision also dropped the previous "legal problems" criterion and added craving — a strong urge to use — as a diagnostic criterion 2Ref 2Hasin DS, O'Brien CP, Auriacombe M, et al. (2013).DSM-5 criteria for substance use disorders: recommendations and rationale.DSM-5 merges abuse and dependence into a single substance use disorder with a 2-or-more-criteria diagnostic threshold; drops the legal-problems criterion and adds craving.

The spectrum: mild, moderate, and severe

Substance use disorder is diagnosed against 11 criteria in the DSM-5, and severity is graded by how many of them a person meets over a 12-month period 3Ref 3Johns Hopkins University (SAMHSA-supported clinical resource) (2024).Substance Use Screening, Risk Assessment, and Use Disorder Diagnosis in Adults (DSM-5-TR criteria).11 DSM-5 criteria in four groups (impaired control, social impairment, risky use, pharmacological); diagnosis requires 2+; severity mild (2-3), moderate (4-5), severe (6 or more); tolerance/withdrawal from medication taken as prescribed under medical supervision do not count toward a diagnosis:

• Mild — 2 to 3 criteria
• Moderate — 4 to 5 criteria
• Severe — 6 or more criteria

Meeting 2 or more of the 11 criteria is the threshold for a diagnosis 3Ref 3Johns Hopkins University (SAMHSA-supported clinical resource) (2024).Substance Use Screening, Risk Assessment, and Use Disorder Diagnosis in Adults (DSM-5-TR criteria).11 DSM-5 criteria in four groups (impaired control, social impairment, risky use, pharmacological); diagnosis requires 2+; severity mild (2-3), moderate (4-5), severe (6 or more); tolerance/withdrawal from medication taken as prescribed under medical supervision do not count toward a diagnosis. The criteria fall into four groups: impaired control (using more or longer than intended, wanting to cut down but failing, spending a lot of time using or recovering, craving); social impairment (failing to meet obligations, continued use despite relationship problems, giving up important activities); risky use (using in hazardous situations, using despite a physical or psychological problem it causes); and pharmacological criteria (tolerance and withdrawal) 3Ref 3Johns Hopkins University (SAMHSA-supported clinical resource) (2024).Substance Use Screening, Risk Assessment, and Use Disorder Diagnosis in Adults (DSM-5-TR criteria).11 DSM-5 criteria in four groups (impaired control, social impairment, risky use, pharmacological); diagnosis requires 2+; severity mild (2-3), moderate (4-5), severe (6 or more); tolerance/withdrawal from medication taken as prescribed under medical supervision do not count toward a diagnosis.

Because it is a spectrum, the same substance can produce a mild disorder in one person and a severe one in another, and severity can change over time — which is why diagnosis focuses on the pattern of criteria met rather than the amount used or the specific substance.

Signs and symptoms

The diagnostic criteria describe the signs clinicians and families tend to notice 3Ref 3Johns Hopkins University (SAMHSA-supported clinical resource) (2024).Substance Use Screening, Risk Assessment, and Use Disorder Diagnosis in Adults (DSM-5-TR criteria).11 DSM-5 criteria in four groups (impaired control, social impairment, risky use, pharmacological); diagnosis requires 2+; severity mild (2-3), moderate (4-5), severe (6 or more); tolerance/withdrawal from medication taken as prescribed under medical supervision do not count toward a diagnosis:

• Strong cravings or urges to use
• Using more, or for longer, than intended
• Repeated unsuccessful attempts to cut down or stop
• A great deal of time spent obtaining, using, or recovering from the substance
• Failing to keep up with responsibilities at work, school, or home
• Continuing to use despite relationship or social problems it causes
• Giving up or cutting back on important activities in order to use
• Using in situations where it is physically dangerous
• Continuing to use despite knowing it is causing or worsening a physical or psychological problem
• Tolerance — needing more of the substance to get the same effect
• Withdrawal — physical or emotional symptoms when the substance wears off

Tolerance and withdrawal alone, when a medication is taken as prescribed under medical supervision, are not counted toward a diagnosis 3Ref 3Johns Hopkins University (SAMHSA-supported clinical resource) (2024).Substance Use Screening, Risk Assessment, and Use Disorder Diagnosis in Adults (DSM-5-TR criteria).11 DSM-5 criteria in four groups (impaired control, social impairment, risky use, pharmacological); diagnosis requires 2+; severity mild (2-3), moderate (4-5), severe (6 or more); tolerance/withdrawal from medication taken as prescribed under medical supervision do not count toward a diagnosis. A clinician makes the diagnosis through a structured interview, sometimes with a validated screening tool, and rules out other explanations for the symptoms.

Medications for opioid use disorder (MOUD)

For opioid use disorder, treatment with methadone, buprenorphine, or naltrexone is the standard of care 6Ref 6National Institute on Drug Abuse (NIDA) (2025).Treatment (Research Topics).Methadone, buprenorphine, or naltrexone is the standard of care for opioid use disorder; behavioral therapies include CBT, contingency management, and motivational enhancement/interviewing; SUDs are chronic, treatable disorders and relapse is often part of the recovery process. These medications — collectively called medications for opioid use disorder (MOUD), and sometimes medication-assisted treatment (MAT) — reduce cravings and withdrawal and, most importantly, lower the risk of death.

A systematic review and meta-analysis of cohort studies found that staying in treatment sharply reduces mortality. Pooled all-cause mortality was 11.3 deaths per 1,000 person-years while in methadone treatment versus 36.1 out of it, and overdose mortality was 2.6 versus 12.7 per 1,000 person-years in and out of methadone treatment. For buprenorphine, all-cause mortality was 4.3 in treatment versus 9.5 out of it. The authors concluded that retention in methadone or buprenorphine treatment is associated with substantial reductions in the risk of all-cause and overdose mortality 4Ref 4Sordo L, Barrio G, Bravo MJ, et al. (2017).Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies.All-cause mortality 11.3 vs 36.1 per 1,000 person-years in vs out of methadone treatment; overdose mortality 2.6 vs 12.7; buprenorphine all-cause 4.3 vs 9.5; retention in methadone/buprenorphine substantially reduces all-cause and overdose mortality.

Because the risk of overdose death is highest in the periods out of treatment — including shortly after stopping — staying engaged in medication treatment is itself protective. Naltrexone, an opioid blocker, is a further option, and take-home naloxone reverses an active opioid overdose.

Medications for alcohol use disorder

Several medications are FDA-approved for alcohol use disorder. A systematic review and meta-analysis of 135 studies concluded that acamprosate and oral naltrexone have the best evidence for improving drinking outcomes 5Ref 5Jonas DE, Amick HR, Feltner C, et al. (2014).Pharmacotherapy for Adults With Alcohol-Use Disorders in Outpatient Settings.Acamprosate and oral naltrexone have the best evidence for alcohol use disorder; NNT to prevent return to any drinking 12 (acamprosate) and 20 (naltrexone 50 mg/day); NNT 12 for naltrexone to prevent return to heavy drinking; evidence from well-controlled trials does not support the efficacy of disulfiram, except possibly for patients with excellent adherence.

In that analysis, the number needed to treat (NNT) to prevent one person from returning to any drinking was 12 for acamprosate and 20 for oral naltrexone (50 mg/day); the NNT to prevent one person from returning to heavy drinking was 12 for oral naltrexone 5Ref 5Jonas DE, Amick HR, Feltner C, et al. (2014).Pharmacotherapy for Adults With Alcohol-Use Disorders in Outpatient Settings.Acamprosate and oral naltrexone have the best evidence for alcohol use disorder; NNT to prevent return to any drinking 12 (acamprosate) and 20 (naltrexone 50 mg/day); NNT 12 for naltrexone to prevent return to heavy drinking; evidence from well-controlled trials does not support the efficacy of disulfiram, except possibly for patients with excellent adherence. Head-to-head trials found no statistically significant difference between the two medications on consumption outcomes 5Ref 5Jonas DE, Amick HR, Feltner C, et al. (2014).Pharmacotherapy for Adults With Alcohol-Use Disorders in Outpatient Settings.Acamprosate and oral naltrexone have the best evidence for alcohol use disorder; NNT to prevent return to any drinking 12 (acamprosate) and 20 (naltrexone 50 mg/day); NNT 12 for naltrexone to prevent return to heavy drinking; evidence from well-controlled trials does not support the efficacy of disulfiram, except possibly for patients with excellent adherence.

Disulfiram is also FDA-approved, but in the same review, evidence from well-controlled trials did not support its efficacy, except possibly for patients with excellent adherence 5Ref 5Jonas DE, Amick HR, Feltner C, et al. (2014).Pharmacotherapy for Adults With Alcohol-Use Disorders in Outpatient Settings.Acamprosate and oral naltrexone have the best evidence for alcohol use disorder; NNT to prevent return to any drinking 12 (acamprosate) and 20 (naltrexone 50 mg/day); NNT 12 for naltrexone to prevent return to heavy drinking; evidence from well-controlled trials does not support the efficacy of disulfiram, except possibly for patients with excellent adherence. Naltrexone is used for both alcohol and opioid use disorder. Medications work best alongside counseling and follow-up rather than on their own.

Behavioral treatments and mutual aid

Behavioral treatments help people build motivation, cope with cravings, and change the patterns around use. Well-studied approaches include cognitive behavioral therapy (CBT), which helps a person manage the thoughts and situations that lead to use; contingency management, which uses small tangible incentives to reinforce staying substance-free; and motivational interviewing (and motivational enhancement therapy), which helps a person resolve ambivalence and strengthen their own reasons to change 6Ref 6National Institute on Drug Abuse (NIDA) (2025).Treatment (Research Topics).Methadone, buprenorphine, or naltrexone is the standard of care for opioid use disorder; behavioral therapies include CBT, contingency management, and motivational enhancement/interviewing; SUDs are chronic, treatable disorders and relapse is often part of the recovery process.

Mutual-aid groups — such as Alcoholics Anonymous (AA), Narcotics Anonymous, and SMART Recovery — provide free, ongoing peer support. A 2020 Cochrane review found that clinician-delivered 12-step facilitation (TSF), which actively connects people to AA, produced higher rates of continuous abstinence than other established treatments. In the landmark Project MATCH trial, 24% of outpatients assigned to AA/TSF were continuously abstinent through the first year, compared with 15% for CBT and 14% for motivational enhancement therapy; AA/TSF also reduced downstream health-care costs 7Ref 7Kelly JF, Abry A, Ferri M, Humphreys K (2020).Alcoholics Anonymous and 12-Step Facilitation Treatments for Alcohol Use Disorder: A Distillation of a 2020 Cochrane Review for Clinicians and Policy Makers.Manualized 12-step facilitation produced higher continuous-abstinence rates than other established treatments; in Project MATCH 24% of AA/TSF outpatients were continuously abstinent at one year vs 15% (CBT) and 14% (MET); AA/TSF reduced health-care costs.

Medication and behavioral treatment are complementary — for many people the combination works better than either alone, and the right mix is often found through some adjustment over time.

Getting help and what to expect

Despite effective treatments, most people who need care do not get it. Of the 48.5 million people classified as needing substance use treatment in 2023, only 15.6% (7.1 million) received any treatment 1Ref 1Substance Abuse and Mental Health Services Administration (SAMHSA) (2024).Results from the 2023 National Survey on Drug Use and Health (NSDUH).In 2023, 48.5 million people aged 12+ (17.1%) had a past-year substance use disorder; 8.9 million misused opioids; of those needing treatment, 15.6% (7.1M) received it. Cost, stigma, and limited access to prescribers are among the reasons.

Help can start with a primary care clinician, an addiction medicine specialist, or a licensed therapist. For opioid and alcohol use disorders, medication is first-line care, not a last resort. Telehealth has expanded access to buprenorphine and to counseling.

For free, confidential help finding treatment, SAMHSA's National Helpline — 1-800-662-4357 — operates 24 hours a day, 365 days a year, in English and Spanish, and connects callers to local treatment and support services 8Ref 8Substance Abuse and Mental Health Services Administration (SAMHSA) (2024).SAMHSA National Helpline.SAMHSA's National Helpline, 1-800-662-4357, is a free, confidential, 24/7 (365-day) treatment referral and information service in English and Spanish. Recovery is not linear; returning to use is common and is a signal to adjust treatment, not to abandon it 6Ref 6National Institute on Drug Abuse (NIDA) (2025).Treatment (Research Topics).Methadone, buprenorphine, or naltrexone is the standard of care for opioid use disorder; behavioral therapies include CBT, contingency management, and motivational enhancement/interviewing; SUDs are chronic, treatable disorders and relapse is often part of the recovery process.