The symptoms of co-occurring disorders are difficult to read because they are the same symptoms that either condition produces on its own. Poor sleep, irritability, low mood, anxiety, and withdrawal from people all belong to substance use and to mental health conditions. That means a list of symptoms will not tell you which you are looking at.
What does help is knowing which patterns point to both rather than one, and that is what this page is for. It covers the signs on each side, the three patterns that suggest a co-occurring condition specifically, what a family member can actually observe from outside, what to do if this is urgent tonight, and how the diagnosis gets made. For what the term itself means and how the two conditions are treated together, see our overview of addiction treatment.
Why the Signs Are Hard to Read
There is a real reason this is confusing, and it is not that you are missing something obvious. Substance use can mimic a mental illness outright; it can worsen one that is already present, and a mental health condition can drive substance use in the first place [1]. The same presentation therefore has at least three possible explanations, and telling them apart from the outside is not reliably possible. Our overview of mental health treatment options covers how the two are considered together.
Self-medication is part of why. Some people use substances in an attempt to reduce anxiety, mood symptoms, or trauma-related distress. Although the short-term effects can feel helpful, continued substance use can reinforce the pattern and may worsen psychiatric symptoms over time. If previous treatment addressed only substance use or only mental health, and problems repeatedly returned, ask whether the other side was assessed. That history can justify a more comprehensive evaluation, but many other factors can also explain an incomplete or temporary treatment response.
In some young people, mental-health symptoms appear before problematic substance use. In others, substance use appears first, and in still others, shared developmental, genetic, or environmental factors contribute to both. Telling a primary mental health condition from substance-induced symptoms usually takes a period of stability rather than a single appointment. That is a clinical judgment, not something to settle at home.
Signs of a Dual Diagnosis
One naming point before the lists, because it affects what you search for. Dual diagnosis is the older term for the same situation, so dual diagnosis symptoms and the symptoms of co-occurring disorders describe one set of signs, not two. Some clinicians and programs still use dual diagnosis, some say co-occurring mental disorders, and a few say co-occurring conditions. None of the labels changes what to look for.
The reason the naming matters at all is that people with one condition are at greater risk of the other, so a search that only covers half the picture returns half the answer. Health outcomes are measurably worse when both conditions are present and only one is treated. That is the practical case for looking at both from the start.
Signs on the Substance Use Side
This side has an advantage: there is an actual diagnostic checklist, and it is more useful than any general list of warning signs. The criteria below are the ones clinicians use, phrased by the National Institute on Alcohol Abuse and Alcoholism as questions about the past twelve months [2]. They are written for alcohol, and the same structure applies to other drugs.
The Eleven Criteria Clinicians Actually Use
In the past year, has the person [2]:
- Ended up drinking more, or longer, than they intended
- More than once wanted to cut down or stop, or tried to, but could not
- Spent a lot of time drinking, being sick from drinking, or getting over the aftereffects
- Wanted a drink so badly they could not think of anything else
- Found that drinking, or being sick from it, interfered with looking after home or family, or caused job or school problems
- Continued to drink even though it was causing trouble with family or friends
- Given up or cut back on activities they found important, interesting or pleasurable in order to drink
- More than once gotten into situations while or after drinking that increased their chances of getting hurt
- Continued to drink even though it was making them feel depressed or anxious, or adding to another health problem
- Needed to drink much more than they once did to get the same effect
- Had withdrawal symptoms as the effects were wearing off
Read it as a list of behaviors rather than a list of quantities, which is the part people get wrong. How much someone drinks is not among the criteria. A high tolerance is, and so is the gap between what they intended and what happened. Our post on the signs of addiction covers the same ground in plainer terms.
The One Criterion That Points at a Co-Occurring Condition
Look again at the ninth item. Continuing to drink even though it was making them feel depressed or anxious is a diagnostic criterion for a substance use disorder, and it is also, read the other way round, a description of a co-occurring problem in progress.
Most people skim past it, because it sounds like a general statement about consequences. It is not. It describes someone whose substance use and whose mood or anxiety are already interacting, and who is continuing anyway. Watch for symptoms that are persistent, recurrent, severe, or causing a meaningful change in functioning. The duration required for diagnosis differs by condition, and some symptoms, such as psychosis or suicidal thoughts, require prompt assessment regardless of how long they have been present.
Psychiatric symptoms that persist well beyond the expected intoxication or withdrawal period increase concern for an independent mental disorder. Even then, diagnosis also depends on the person’s prior history, the substance involved, the symptom pattern, and clinical evaluation.
How Severity Is Judged
Severity comes from how many criteria are met in the same twelve months: mild is two to three, moderate is four to five, and severe is six or more [2]. Nothing about the count depends on what the substances involved were, or on whether the person has lost a job or a license.
This matters for families because the threshold is lower than most people assume. Two criteria is a diagnosis. A person can meet the definition of a mild alcohol use disorder while holding a demanding job, which is why waiting for a visible collapse before raising it is a mistake.
Signs on the Mental Health Side
The mental health side has no equivalent checklist a family member can apply, because the criteria differ by condition and several of them require information only the person has. What you can watch for is change and duration.
Anxiety, Mood, and Sleep Signs
The signs that matter are the ones that persist for weeks rather than days and that represent a shift from how the person normally is. They include sleep problems in either direction, appetite change, loss of interest in things they used to want, irritability out of proportion to events, and a flatness that does not lift with good news.
The behavioral signs are usually easier to see than the emotional ones. Observable changes may include social withdrawal, missed responsibilities, major changes in sleep or appetite, unusual irritability, emotional instability, reduced self-care, or behavior that is markedly different from the person’s baseline.
Which condition is in play changes the picture. Anxiety disorders, major depression, bipolar disorder, post-traumatic stress disorder, and impulse control disorders all travel with substance use, and each produces a different pattern of mental health problems. You are not naming the condition from outside, only noticing that something shifted and stayed shifted.
Anxiety may appear as avoidance, reassurance seeking, excessive worry, physical tension, panic attacks, sleep disruption or a shrinking range of activities.
The shape of a mood change matters as much as its direction. Watch for periods of unusually elevated, expansive, or irritable mood. When those come with changes such as decreased need for sleep, increased activity, pressured speech, or risky behavior, they warrant assessment for mania or hypomania. Bipolar disorder does not always involve regular alternation between depression and elevated mood.
Signs That Mean Do Not Wait
Some signs change the timeline. Talk of not wanting to be here, giving away possessions, a sudden calm after a long stretch of despair, losing touch with what is real, or an inability to keep themselves safe or fed all qualify.
If any of that is present, skip the rest of this page and go to the crisis section below. Waiting for more certainty is the wrong call in that situation, and the people on the other end of a crisis line are used to being called by someone who is not sure.
Signs That Point at Both Rather Than One
These patterns cannot diagnose a co-occurring disorder, but they give a clinician useful information and are good reasons to assess both substance use and mental health.
Symptoms That Do Not Lift When Use Stops
The clearest signal. If the person has had a stretch of real abstinence, weeks rather than days, and the low mood or anxiety is still there at the end of it, that argues for a mental health condition in its own right. It is not one produced by the substance.
Symptoms that consistently improve as intoxication and withdrawal resolve may be substance-induced, but the expected timeline varies by substance and cannot be reduced to a two-week rule. One other possibility is worth ruling out in Minnesota. A mood dip that arrives with the calendar rather than with the drinking may be seasonal, and our post on the effects of seasonal depression in Minnesota covers that pattern. Neither pattern is proof. This is exactly the judgment a comprehensive assessment exists to make, but it is the most useful observation a family can bring to one.
A History of Treatment That Half-Worked
If the person has been through treatment before and it held for a while and then did not, ask what was treated. A common history is mental health care that never addressed the substance use, or substance use treatment that never addressed the mental health condition, followed by a return to where they started.
That pattern is far more common than it should be. Of the 21.2 million US adults who had both a mental illness and a substance use disorder in 2024, about 2 in 5 did not receive treatment for either condition. Among those who did receive something, most received help for only one side [3]. Work the numbers through and roughly 1 in 7 of everyone with both conditions received treatment for both. A history of treatment that half worked is often a history of only half the problem being treated.
Other factors can explain a treatment that stopped working, including a change in circumstances or the arrival of other mental health disorders that were not present the first time. But when someone has been through care more than once, and each round addressed a single condition, that is the likeliest explanation. It is worth saying out loud at the next appointment.
Use That Rises and Falls with the Symptoms
Watch the timing rather than the amount. Where drinking or drug use climbs during a bad stretch and eases when things are steadier, the two are linked in a way that treating either alone will not resolve. The link can run in either direction, and from outside you cannot tell which, only that the two move together.
Families often notice this pattern years before anyone names it, and describe it as the person coping rather than as a disorder. Both descriptions can be accurate at once, and saying so out loud is often what makes the conversation possible: coping is not a moral failure, and naming it as coping is not the same as excusing it.
Physical Health Conditions That Travel with Both
People with SUDs also commonly have important physical-health comorbidities, including chronic pain, cardiovascular disease, and infectious diseases. These medical conditions are clinically important, although they are not what this article means by the behavioral-health term “co-occurring disorders.”
NIDA notes that substance use disorders commonly occur alongside physical health conditions, including chronic pain, heart disease, and HIV, hepatitis, and other infectious diseases [1]. Those medical conditions matter to recognition for two reasons.
First, chronic pain is a common route into a substance use disorder, and it complicates treating one. It belongs in the history rather than in a separate conversation with a different doctor. People in this position often receive medical care and behavioral health care from teams that never speak to each other. Professional medical care for the physical condition should be part of the same plan rather than parallel to it. Second, physical decline is often the sign a family notices first, because it is visible: weight change, dental problems, recurring infections, injuries with vague explanations.
Risk Factors That Change What You Look For
Risk factors are not symptoms, but they raise the odds enough to be worth knowing. Childhood trauma increases the likelihood of both conditions. That includes emotional abuse, sexual abuse, and emotional or physical neglect, not only the events people expect. A person’s genes contribute substantially to both, and environmental factors, including chronic stress and early exposure to substances, do the same work.
Part of why common risk factors matter is mechanical. Substance use disorders and mental illnesses involve some of the same brain areas, which is one reason the two develop together rather than one simply following the other. Our guidance on managing anxiety is the practical companion where trauma is part of the history. The three causal pathways are set out in full on our explainer page linked above.
How Do I Tell if Someone I Know Has a Co-Occurring Disorder?
You cannot diagnose it, and you do not need to. What you can do is gather the observations a clinician cannot make, because you are the one who sees this person on ordinary Tuesdays.
What Family Members Can Observe
Note patterns and dates rather than incidents. When did the change start? What has stopped happening that used to happen? Does use track the bad stretches? Has there been a period without substances, and what was the mood like at the end of it? Are there risky behaviors that are new?
Write it down before the appointment, because the useful details are the ones that get forgotten under pressure. Family members can provide valuable collateral information about when changes began, what functioning looked like before substance use escalated, and how symptoms changed during periods of abstinence.
How to Raise It Without a Confrontation
Pick a sober moment and a private one, name what you have seen rather than what you have concluded, and ask rather than tell. “You have seemed flat for months, and I have noticed the drinking has gone up” is a sentence someone can respond to. “You are an alcoholic, and you are depressed” is one they have to defend against.
Do not expect one conversation to resolve everything. The person may be receptive, defensive, uncertain, or somewhere in between, and more than one conversation may be needed.
What to Do If This Is a Crisis
Having both conditions raises the odds of reaching a crisis point rather than a slow decline, and SAMHSA documents a higher risk of homelessness, incarceration, and suicide where both are present than where only one is [3]. It is worth knowing what to do before you need to know it.
If someone is in immediate danger, call 911. If you are worried about their safety but it is not an emergency, call or text 988 to reach the Suicide and Crisis Lifeline, which handles substance use crises as well as mental health ones.
Minnesota’s Mobile Crisis System
Minnesota also has a mobile crisis system worth knowing about before you need it. Under state law, crisis response services include mobile crisis screening, assessment, intervention and community-based stabilization. They must be available 24 hours a day, seven days a week, through county boards, Indian health services facilities or contracted providers. Each team must include at least one mental health professional on staff at all times, plus one additional staff member able to lead a crisis response in the community [4].
What that means in practice is that a team can come to the house rather than requiring you to get someone into a car. Each county publishes its own crisis number, and the state maintains a directory of them. The useful five minutes to spend today is finding your county’s number and putting it in your phone before there is any reason to call it.
What a Crisis Team Cannot Refuse
Here is the part families are rarely told. The same statute requires providers to serve an eligible person who has a co-occurring substance use disorder, where they do not need acute inpatient care, and to coordinate with their other health care providers [4]. A Minnesota mobile crisis team is not entitled to turn someone away because they had been drinking or using when the crisis happened.
If you have been told otherwise, that is worth pushing back on, and it is worth writing down who said it. Sometimes withdrawal itself is the medical risk rather than the mental health crisis. In that case, clinically managed and medically monitored withdrawal management is the level of care that addresses it, and a crisis line can help you work out which of the two you are dealing with.
How the Diagnosis Actually Gets Made
Two things reassure people here. The first is that you do not have to arrange two separate evaluations to get both conditions looked at. Minnesota law requires the comprehensive assessment for substance use disorder services to include a determination of whether the person screens positive for co-occurring mental health disorders, using a screening tool approved by the commissioner [5]. A positive mental health screen is not the same as a psychiatric diagnosis, however, and some people will need an additional diagnostic mental-health assessment.
The second is that a person can request that assessment directly from a provider rather than going through a county first. Our explainer on the rule 25 assessment and what replaced it covers how that works now, including who is qualified to complete one.
Common Questions About Co-Occurring Symptoms
Can Substance Use Cause a Mental Illness?
It can contribute to one. Sustained heavy use changes brain systems involved in mood, stress, and impulse control, and in some people psychiatric symptoms persist after use stops, which is when a separate diagnosis becomes appropriate.
The practical answer for a family is that the question rarely needs settling before someone can enter treatment. Some intoxication-related symptoms resolve relatively quickly, while withdrawal or post-acute symptoms from substances such as stimulants can persist for weeks. The expected course depends on the substance, dose, duration of use, and individual vulnerability.
Research supports treating both conditions together rather than separately; NIDA’s research report, hosted by the National Library of Medicine, is the accessible summary of that evidence [1].
Do Support Groups Help with Both?
They help, and they are not sufficient on their own. Support groups, including Alcoholics Anonymous and other twelve-step program meetings, supply emotional and social support that clinical care does not, and social support is among the more consistent predictors of how recovery goes.
If a group discourages a medication prescribed by a qualified clinician, discuss that advice with the prescriber rather than changing medication based on peer guidance. Look for groups that are explicit about welcoming people with co-occurring conditions, and treat them as one part of a plan rather than the plan. Our overview of outpatient mental health care covers the clinical side that runs alongside.
Getting an Assessment in Minnesota
If more than a couple of the criteria above fit, or if you have noticed symptoms that did not lift during a substance-free stretch, an assessment is the reasonable next step rather than more watching.
NorthStar Regional treats substance use disorders and mental health conditions together across the Twin Cities metro, including intensive outpatient options for people who need structure without leaving work or home. Anyone can request an assessment, including a family member calling on someone else’s behalf, and our team can be reached through our contact page. Our post on emotional sobriety covers the stretch that comes after the first appointment.
Sources
- National Institute on Drug Abuse. Common Comorbidities with Substance Use Disorders Research Report. April 2020. https://www.ncbi.nlm.nih.gov/books/NBK571451/
- National Institute on Alcohol Abuse and Alcoholism. Understanding Alcohol Use Disorder. Updated January 2025. https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/understanding-alcohol-use-disorder
- Substance Abuse and Mental Health Services Administration. Key Substance Use and Mental Health Indicators in the United States: Results from the 2024 National Survey on Drug Use and Health. July 2025. https://www.samhsa.gov/data/report/2024-nsduh-annual-national-report
- Minnesota Statutes 256B.0624, Crisis Response Services Covered. Amended 2026. https://www.revisor.mn.gov/statutes/cite/256B.0624
- Minnesota Statutes 245G.05, Comprehensive Assessment and Assessment Summary. Amended 2025. https://www.revisor.mn.gov/statutes/cite/245G.05
