Concurrent disorders means living with a mental illness and a substance use problem at the same time, and because the two feed each other, the care that works best treats both together rather than one after the other.

If you or someone you love is dealing with anxiety, depression, or trauma alongside drinking or drug use, you are in a situation that is common and treatable. In Ontario this pairing is frequent enough to have its own clinical name and its own approach to care.

This article is for general education. If you want to understand the mental health side of recovery, our mental health treatment page explains how we support it alongside addiction care.

What are concurrent disorders?

Concurrent disorders describe any combination of a mental health problem and a substance use problem happening together. The Centre for Addiction and Mental Health (CAMH) uses the term broadly, so it covers pairings like an anxiety disorder with heavy drinking, depression with opioid use, or post-traumatic stress with cannabis use. There is no single symptom shared by every combination, which is part of why these situations are missed so often.

One point confuses a lot of people, and it matters in Ontario. Here, “dual diagnosis” usually means a mental illness alongside a developmental disability, which is a different clinical area. The term for a mental illness plus a substance use problem is concurrent disorders. In the United States and some other places, “dual diagnosis” is used the way Canadians use concurrent disorders, so you will see the words treated as interchangeable online even though the Ontario health system keeps them separate.

How common are concurrent disorders?

They are common. CAMH reports that at least 20 percent of people with a mental illness also have a co-occurring substance use problem, and that people with a mental illness are about twice as likely to have a substance use disorder compared with the general population. For people living with schizophrenia, the figure may be as high as 50 percent. It runs the other way too, with more than 15 percent of people who have a substance use disorder also living with a mental illness.

Numbers like these are a reminder that struggling with both is not a personal failing or a rare complication. It is one of the more predictable patterns in addiction medicine, which is exactly why good clinics plan for it.

Why mental illness and addiction often overlap

There is rarely one clean cause. Mental health and substance use tend to pull on each other in several directions at once, and CAMH describes a few of the common ways this happens.

• Self-medication: People use alcohol or drugs to quiet symptoms like anxiety, low mood, racing thoughts, or trauma memories. The relief is short, and the underlying condition usually gets harder to treat.
• Substances worsening symptoms: Many drugs deepen the very problems people are trying to escape, so depression gets heavier or anxiety rebounds stronger once the substance wears off.
• Masking and mimicking: Substance use can hide a mental illness or imitate its symptoms, which makes an accurate diagnosis harder until the substance use is addressed.
• Medication interference: Some substances make psychiatric medications less effective, and missed doses during heavy use can lead to relapse or a return of symptoms.
• Shared roots: Genetics, early stress, and trauma raise the risk of both conditions, so the same life history can set the stage for each one.

Common combinations to know

Any mental health condition can appear with any substance, but a few pairings show up again and again in practice. The table below is a general guide, not a diagnosis.

Signs it might be a concurrent disorder

You do not need to sort out which problem came first to ask for help. A few patterns are worth paying attention to.

• Using to cope: Drinking or using mainly to manage mood, sleep, panic, or intrusive memories rather than for enjoyment.
• Treatment that stalls: Mental health symptoms that do not improve with therapy or medication while substance use continues, or the reverse.
• A cycle of relapse: Getting stable, then slipping back when either the mood symptoms or the cravings return.
• Symptoms that shift with use: Anxiety, depression, or paranoia that rise and fall alongside drinking or drug use.
• Everyday life slipping: Work, relationships, and health all affected, with both conditions feeding the strain.

If this sounds familiar, a professional assessment can tell you what is going on and what would actually help. Our guide on the signs you may need help walks through this in plain terms, and if you are new to the idea of treatment, what addiction actually is is a good place to start.

How concurrent disorders are treated

The approach with the best track record is integrated treatment, where the mental illness and the substance use are addressed at the same time and by a coordinated team. Treating one and ignoring the other tends to leave the untreated condition to pull the person back, which is how so many people end up cycling through separate systems without lasting progress.

Care usually combines a few pieces, matched to the person rather than applied as a fixed package:

• Assessment: A clinician looks at both the mental health and the substance use together, so the plan fits the whole picture.
• Medication: This can include psychiatric medication for the mental illness and, where it fits, medication-assisted treatment for alcohol or opioid use.
• Counselling and therapy: Approaches like cognitive behavioural therapy and motivational interviewing help with both sides at once.
• Stabilizing first when needed: Sometimes one problem is steadied before the full plan moves ahead, for example managing heavy alcohol use or acute withdrawal. If you are wondering about that step, detox and when it needs medical support covers the basics.
• Ongoing support: Regular follow-up, relapse prevention, and help with housing, income, and daily needs keep recovery from unravelling.

Detox, medication, therapy, and aftercare each do a different job, and a good plan usually uses more than one. The point of integrated care is that the same team keeps both conditions in view the whole way through.

Getting OHIP-covered treatment for concurrent disorders in Ontario

Thrive Medical is a Rapid Access Addiction Medicine (RAAM) clinic serving North York and the Greater Toronto Area, with virtual appointments available across Ontario. Assessment and medical treatment are covered by OHIP for eligible patients, so you can get started without a referral and without a long wait.

For concurrent disorders, that means a clinician can look at both the substance use and the mental health side, start medication where it helps, and connect you with counselling and follow-up. You can read how our virtual outpatient program works, what is included under OHIP-covered addiction treatment, and if a family doctor or agency is helping you, how referrals fit in. When you are ready, you can contact our team to book a confidential assessment.

Frequently Asked Questions

What are concurrent disorders?

Concurrent disorders means having a mental illness and a substance use problem at the same time. CAMH uses the term for any combination of the two, such as anxiety with heavy drinking or depression with opioid use. Because the conditions interact, treating them together usually gives better results than treating one alone.

What is the difference between concurrent disorders and dual diagnosis?

In Ontario the terms are not interchangeable. Concurrent disorders means a mental illness plus a substance use problem. Dual diagnosis here usually means a mental illness alongside a developmental disability. Elsewhere dual diagnosis is often used the way Canadians use concurrent disorders, which is where the confusion comes from.

How common are concurrent disorders?

Common. CAMH reports that at least 20 percent of people with a mental illness also have a substance use problem, and that people with a mental illness are about twice as likely to have one. Among people living with schizophrenia the figure may reach 50 percent.

Should the addiction or the mental illness be treated first?

Usually both at once. Integrated treatment addresses the mental health and the substance use together in a coordinated way, which research links to the best outcomes. Sometimes one problem is stabilized first, such as heavy alcohol use or acute withdrawal, before the full plan moves forward.

Can concurrent disorders be treated through virtual care?

Often yes. Many people manage assessment, medication, counselling, and follow-up through virtual appointments, which removes travel and shortens the wait. More acute situations, such as severe withdrawal or active psychosis, may need in-person or hospital care first, with virtual follow-up after.

Is treatment for concurrent disorders covered by OHIP?

Assessment and medical treatment at a RAAM clinic like Thrive Medical are covered by OHIP for eligible patients. Some add-on counselling or specialized programs can have separate costs, so it helps to confirm what is included when you book your appointment.

Sources

• Centre for Addiction and Mental Health (CAMH), Concurrent Disorders
• Centre for Addiction and Mental Health (CAMH), Mental Illness and Addiction: Facts and Statistics
• Canadian Mental Health Association (CMHA), Concurrent Mental Illness and Substance Use Problems
• Government of Canada, Health Canada, Substance use and concurrent disorders
• Danilewitz M, Concurrent Disorders Management in Psychiatric Care (2021)

Last reviewed: November 2026. This article is for general educational purposes and does not replace medical advice. Talk to a licensed healthcare provider about your specific situation. If you or someone you are with is having thoughts of suicide or a medical emergency, call 911 or go to the nearest emergency department.