Key takeaway
A co-occurring disorder means at least one mental disorder and one substance use disorder at the same time. SAMHSA's 2024 survey estimates 21.2 million U.S. adults were in that group. Integrated care treats both together. Screening for only one problem leaves the other untreated.
Last updated: Mon Oct 05 2026 00:00:00 GMT+0000 (Coordinated Universal Time)
Two diagnoses can look like one crisis. A person drinks because panic will not stop, or uses opioids because sleep and mood collapsed, and then the substance use makes the mood worse. SAMHSA's name for having both a mental disorder and a substance use disorder is co-occurring disorders. Families often say dual diagnosis. The practical point is the same: the plan has to cover both, or the untreated half pulls the person back.
If someone is in immediate danger of suicide, is seizing, or cannot be woken, call 911. For a mental health crisis, call or text 988. A referral conversation can wait until the person is safe.
What the term covers
SAMHSA says co-occurring disorders may include any combination of two or more substance use disorders and mental disorders identified in the DSM-5-TR. No specific pair is the official combination. Anxiety, mood disorders, schizophrenia, bipolar disorder, major depression, post-traumatic stress disorder, and attention deficit hyperactivity disorder are among the mental disorders the agency lists as common. The substances people in mental health care often misuse include alcohol, tobacco, opioids, stimulants, marijuana, hallucinogens, and prescription drugs.
The agency's 2024 National Survey on Drug Use and Health estimates that about 21.2 million adults had a co-occurring mental illness and substance use disorder. People with mental illness are at higher risk of a substance use disorder than people without mental illness. People with substance use disorders are also more vulnerable to other chronic conditions. Those are risk statements, not a prediction for one person.
SAMHSA's advisory based on TIP 42, citing NIDA, says people with substance use disorders are more likely than people without them to have a co-occurring mental disorder, and that these disorders are treatable.
Why separate clinics miss people
The same advisory describes a cascade. If nobody screens, nobody assesses. If nobody assesses, nobody diagnoses. If nobody diagnoses, nobody treats, and the chance of lasting recovery from either disorder drops. Many people with both conditions receive treatment for only one, or for neither.
Integrated care is SAMHSA's preferred model. The practice principles are concrete. The substance use disorder and the mental disorder are treated at the same time, so the full range of symptoms is in view. Staff are trained in both. Care moves in steps that match readiness, from engagement through relapse prevention. Motivational counseling is part of the work, especially early. Addiction counseling is used to build different thoughts and habits. People are offered more than one format: individual, group, family, and peer support. Medicine is discussed by a multidisciplinary team, offered when it fits, and watched for interactions, adherence, and response.
NIDA's research report on comorbidities reaches the same conclusion from the study literature: integrated treatment for a drug use disorder and a mental illness has been found consistently superior to treating each diagnosis separately. Integrated care often uses cognitive behavioral strategies for coping and relationships, plus approaches that support motivation and functioning. NIDA also notes that people with a mental illness are more likely to drop out of treatment than people without one, which is a reason to keep both conditions on the same plan rather than a reason to drop the mental health care.
SAMHSA says there is no wrong door. A primary care clinic, a mental health center, or a substance use program can start the screening. The door still has to open onto both problems.
Screening is a yes-or-no, then a real assessment
SAMHSA describes screening as a formal check that answers a narrow question: does this person, who already has a substance problem or a mental disorder, show signs of the other? A yes leads to assessment, not to a label slapped on a brochure.
The assessment in the TIP 42 advisory looks at biology, including medical conditions and family history; psychology, including past diagnoses, coping, and stress; and social life, including relationships, housing, work, and whether care is actually reachable. It includes a history of symptoms, past treatment, and how much each disorder gets in the way of ordinary life. It also notes the person's stage of change. That history is what should drive the plan. A one-page intake that asks only "what is your drug of choice" does not do this job.
The advisory says people with co-occurring disorders have a higher risk of self-harm, especially with a trauma history. Safety comes first. Staff need to know how to notice suicidal thoughts and what to do next. If that risk is active tonight, use the emergency numbers above before you compare programs.
Levels of care, without a single building type
SAMHSA says people should be placed, when possible, in a level of care that fits how severe the symptoms are, how the person is functioning, and what the recovery environment is like, for both disorders. Several tools exist for clinicians. The advisory names the Level of Care Utilization System and the Four Quadrants Model, which sorts people by whether each disorder is lower or higher severity. You do not have to score yourself. You can ask a program which tool it uses and which facts drove the recommendation.
ASAM's public description of its criteria says level-of-care recommendations come from a multidimensional assessment of biomedical, psychological, and social needs, and that payers using the criteria are aiming for the least intensive level that is still safe. The program comparison guide walks through that idea. The IOP and partial hospitalization guide sits in the middle of the outpatient band. Neither guide assigns you a level from a paragraph.
Settings in the TIP 42 advisory are varied on purpose. Some outpatient programs offer many hours a week and can include mental health services. Others offer one or two brief sessions and a referral. Residential care ranges from long-term programs to short stays, so the word "residential" is not a promise of any particular length. Hospital and emergency care are for withdrawal or symptoms that need round-the-clock medical supervision. Those units may not deliver integrated treatment during a short stay. What they can do is assess and refer once the person is stable.
People move among these settings. SAMHSA's point about continuity is that services should connect as someone steps up or down, and that past treatment should be visible to the current team. A fresh start that throws away the last prescriber's notes is a gap, not a virtue.
Medicine belongs in that conversation. The advisory says pharmacology can be safe and effective for many people with co-occurring disorders, and that counselors who cannot prescribe should still know common side effects and risks. SAMHSA's public co-occurring page warns that combining medicines used for substance use disorders with benzodiazepines for anxiety can have serious adverse effects. Do not stop either medicine on your own to "simplify" the list. The benzodiazepine guide explains why cutting those medicines off in a hurry can bring on seizures. The medication guide covers methadone, buprenorphine, and naltrexone without doses. The alcohol timeline gives the parallel warning for drinking.
Questions that separate a real program from a slogan
Before you accept a bed or a group schedule, ask:
- Who screens for both a mental disorder and a substance use disorder, and with what tool?
- Is psychiatric care in the building, or is it a name on a referral list with no appointment?
- Will prescribed psychiatric medicine and addiction medicine be continued, and who watches interactions?
- What happens on the night symptoms spike after the group ends?
- If alcohol or benzodiazepines are involved, where would a seizure be treated?
A program that treats only the substance, and tells the person to deal with depression after discharge, is not following SAMHSA's concurrent-treatment principle. A program that treats only the mood disorder, and ignores daily opioid use, is not either.
How to start
Search FindTreatment.gov and ask specifically about co-occurring mental health care, not only detox or a 12-step group. National survey differences by sexual identity are a separate page, the LGB+ survey guide, and they are not a diagnosis. Call or text (800) 653-9376 to talk through levels of care. The conversation is not a diagnosis.
Additional Resources
Sources cited on this page:
- SAMHSA: Co-Occurring Disorders and Other Health Conditions
- SAMHSA Advisory: Substance Use Disorder Treatment for People with Co-Occurring Disorders (based on TIP 42)
- NIDA: Common Comorbidities with Substance Use Disorders (research report)
- ASAM: About The ASAM Criteria
- SAMHSA FindTreatment.gov
- 988 Suicide & Crisis Lifeline
Common Questions
What is a dual diagnosis or co-occurring disorder?
SAMHSA uses co-occurring disorders for the presence of both a mental disorder and a substance use disorder. Any combination counted in the DSM-5-TR can qualify. No single pair, such as depression plus alcohol, is the only definition.
Why not treat one problem first and the other later?
SAMHSA's practice principles say the substance use disorder and the mental disorder should be treated at the same time, so the full set of symptoms is covered. NIDA reports that integrated treatment has been consistently better than separate treatment of each diagnosis. Sequential care is how people fall out of one clinic while the other condition gets worse.
How common is this?
SAMHSA's 2024 National Survey on Drug Use and Health estimates that about 21.2 million adults had both a mental illness and a substance use disorder. People with mental illness have a higher risk of a substance use disorder than people without one, and the reverse is also true.
Does every rehab treat mental illness?
No. SAMHSA says programs should be able to screen, assess, and match people to a level of care that fits both conditions, and that many people still receive care for only one. Ask who on the team is trained in both, and whether psychiatric medicine is continued or coordinated. A brochure that says dual diagnosis is not the same as a clinician who can treat it.
Which setting is the right one?
SAMHSA says clients should be placed at a level that matches symptom severity, day-to-day functioning, and the recovery environment for both disorders. Outpatient, intensive outpatient, residential, and hospital care can all be part of that. Acute hospital care is for withdrawal or symptoms that need 24-hour medical supervision. No overview can assign you a level.