Clinically Reviewed by Linda Whiteside, LPCC

Medically Reviewed by: Dr. Ryan Peterson, MD

Dual Diagnosis vs Co-Occurring Disorders: Differences and Similarities

Table of Contents

Let’s talk about two important terms in mental health: dual diagnosis and co-occurring disorders. These are medical terms doctors use when someone has both mental health disorders and substance use disorders. Knowing these terms is key to understanding how to help people with these conditions.

Dual Diagnosis

Dual diagnosis” is when a person has a mental health disorder like depression or anxiety and a substance use disorder at the same time. This could involve drugs, alcohol, or both. It’s very important that we treat both conditions together, not one at a time.

Many people with mental health issues also have problems with substance use. Studies show that about 50% of individuals with severe mental disorders are affected by substance abuse. And 37% of alcohol abusers, along with 53% of drug abusers, also have at least one serious mental illness.

Diagnostic Criteria

When diagnosing dual diagnosis and co-occurring disorders, mental health professionals must go through a careful process. They use guides like the Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association.

It’s important to remember that dual diagnosis is often tricky to diagnose because symptoms of one disorder can sometimes look like symptoms of the other. For example:

  • Someone dealing with depression (a mental health disorder) may use alcohol or drugs (substance misuse) to self-medicate and temporarily ease feelings of sadness or despair. In this case, it can be hard to separate the symptoms of depression from the effects of substance misuse.

  • A person with bipolar disorder (a mental health condition) may have periods of extreme mood changes. When in a ‘high’ or manic phase, they might engage in risky behaviors such as drug abuse. Again, it can be tough to tell if the risky behavior is due to bipolar disorder or a co-occurring substance abuse problem.

  • Major depressive disorder (a severe mental illness) might lead a person to drug addiction as a means to cope with overwhelming feelings of sadness or hopelessness. The symptoms of major depressive disorder, like low energy or feelings of worthlessness, may become intertwined with the effects of the drug addiction, like withdrawal symptoms.

  • Individuals with an intellectual disability (a mental health condition) are also at risk of developing substance-related disorders. They might use substances to fit in socially or manage feelings of frustration or isolation.

Co-Occurring Disorders

“Co-occurring disorders” is another term doctors use when someone has a mental health disorder and a substance use disorder at the same time. This is quite common. The Substance Abuse and Mental Health Services Administration reports that about 9.2 million adults in the U.S. had co-occurring disorders in 2021. Like with dual diagnosis, both conditions need treatment.

Co-occurring disorders present major challenges when both a mental disorder and substance abuse occur. These dual conditions significantly affect one’s work, education, and personal relationships.

Work performance often suffers due to the cognitive effects of mental illnesses such as depression and anxiety, alongside substance abuse’s physical and behavioral effects. School or college performance of young adults is also impacted due to decreased motivation, behavioral issues, and cognitive impairment associated with these disorders. In the personal sphere, establishing and maintaining relationships can be difficult due to emotional instability and social isolation often accompanying these disorders.

Dual Diagnosis vs Co-Occurring Disorders: Key Differences

Dual Diagnosis vs Co-Occurring Disorders_ Key Differences

Terminology and Approach

While the terms “dual diagnosis” and “co-occurring disorders” are often used interchangeably, some experts apply them with subtle distinctions in mind. Typically, both terminologies refer to the simultaneous occurrence of mental health conditions and substance abuse disorders. However, the term “dual diagnosis” is sometimes specifically used when discussing individuals with developmental disorders, such as autism, who also exhibit mental health disorders. This distinction rests upon the following factors:

  • The degree of interaction between the two conditions.

  • The sequence in which the disorders developed.

  • The specific types of mental illnesses and substance use disorders involved.

Diagnostic Criteria and Assessment

When it comes to identifying dual diagnosis or co-occurring disorders, doctors employ various approaches, each requiring unique diagnostic criteria and assessment tools.

In dual diagnosis:

  • Medical professionals primarily look for signs of substance use disorders, which may include symptoms such as withdrawal symptoms or uncontrolled drug use.

  • They also search for indications of common mental health conditions like depression, anxiety, or bipolar disorder. Symptoms might involve mood swings, persistent feelings of sadness, or extreme anxiety.

In the case of co-occurring disorders:

  • Doctors follow a similar approach but may utilize different assessment tools or follow distinct guidelines.

  • They seek to identify both substance abuse and mental health disorders, but the key difference lies in the type of mental disorders they look for – typically, more severe mental illnesses like schizophrenia or personality disorders.

Treatment Approaches and Integration

The treatment of both dual diagnosis and co-occurring disorders necessitates an integrated approach, addressing both the mental health disorder and the substance use disorder simultaneously. Nevertheless, the specific methods of this treatment can vary depending on the classification of the diagnosis. This integrated approach includes:

  • Tailored substance abuse treatment: This may include detoxification for drug use, counseling, or 12-step programs for individuals with substance use disorders.

  • Specific mental health treatment: Therapies such as cognitive-behavioral therapy, dialectical behavior therapy, or medication might be employed to treat mental illness.

  • Social support: Encouraging the individual’s engagement with support groups, family therapy, or community resources can provide additional aid in recovery.

In essence, the choice between “dual diagnosis” and “co-occurring disorder” terminology and treatment can be influenced by the patient’s specific needs, the severity of their mental health conditions, and the type of substance abuse disorders they exhibit. Regardless of terminology, a crucial part of any treatment plan includes concurrently receiving treatment for both disorders, offering the best chance of successful recovery.

Similarities between Dual Diagnosis and Co-Occurring Disorders

Similarities between Dual Diagnosis and Co-Occurring Disorders

Overlapping Symptoms and Comorbidity

Both dual diagnosis and co-occurring disorders involve a combination of mental health disorders and substance use disorders, often exhibiting similar symptoms. Due to the complex interplay of these disorders, distinguishing between them can be a clinical challenge. Comorbidity, or the presence of two or more disorders in an individual, is a common feature of both dual diagnosis and co-occurring disorders. This may manifest as:

  • Multiple mental health disorders: An individual might suffer from depression and anxiety simultaneously.

  • Multiple substance use disorders: An individual might struggle with drug abuse and alcohol use disorder concurrently.

Risk Factors and Underlying Causes

Various factors can increase a person’s susceptibility to developing dual diagnosis or co-occurring disorders. Many of these risk factors overlap for both conditions, including:

  • Family history: A person is at a higher risk if they have relatives with mental health disorders or substance use disorders.

  • Stress: Chronic stress can lead to mental health issues and promote substance abuse as a coping mechanism.

  • Past trauma: Events such as childhood abuse, military combat, or experiencing a disaster can lead to post-traumatic stress disorder (PTSD), which may, in turn, be linked to substance abuse.

  • Environmental factors: Social isolation, poverty, or exposure to drug use can contribute to the development of these conditions.

These disorders frequently affect each other, with the mental health issue often exacerbating the substance abuse problem and vice versa.

Integrated care is key in treating both dual diagnosis and co-occurring disorders. This means health professionals from different fields, like psychiatry and addiction treatment, need to work together.

Treatment Strategies and Interventions

Pharmacological Interventions

Doctors often use medicine to treat mental health disorders and substance use disorders. But this can be hard because some medicines can be addictive.

Psychotherapy and Counseling

Different types of talk therapy can help people with dual diagnosis and co-occurring disorders. These therapies help people learn to manage their symptoms, cope with stress, and change unhealthy behaviors.

Holistic and Supportive Approaches

Taking care of the whole person is important in treatment. This can mean helping the person eat well, exercise, and get enough sleep. Support groups can also be a big help.

Recovery and Relapse Prevention

Recovery means managing both conditions so the person can live a happy, healthy life. It’s not always easy, but it is possible with the right treatment and support. Some examples of recovery activities include:

  • Therapy and counseling

  • Medication management

  • Support group

  • Healthy lifestyle changes

A key part of treatment is avoiding a return to substance use or relapse. This can involve learning to avoid triggers or things that make the person want to use substances again. Examples of relapse prevention activities include

  • Recognizing and managing triggers

  • Developing healthy coping skills

  • Regular follow-up and check-ins

  • Continued participation in support groups

  • Creation of a personalized relapse prevention plan


Dual diagnosis and co-occurring disorders are medical terms for when someone has a mental health disorder and a substance use disorder. They can be hard to treat, but people with these conditions can recover and live healthy lives with the right approach. If you or someone you know might have these conditions, it’s important to get help.

Begin Your Recovery Journey with NuView Treatment Center

Begin Your Recovery Journey with NuView Treatment Center

Facing dual diagnosis or co-occurring disorders? Let NuView Treatment Center guide your path to recovery. Our specialized team offers integrated treatment designed to fit your unique needs. Don’t let mental health and substance use disorders control your life. Contact NuView today – take the first step towards a healthier, brighter future.

Frequently Asked Questions

Treating a co-occurring disorder can be more complex due to the interaction of multiple mental health conditions and substance abuse problems. This necessitates an integrated treatment approach, where both issues are addressed simultaneously. The treatment team needs to perform a comprehensive assessment and formulate an appropriate treatment plan, often involving individual and group therapy.

Integrated treatment is important because mental illness and substance abuse symptoms can overlap, making it difficult to treat them separately. This approach ensures that the treatment team addresses all aspects of the person's health, from psychiatric symptoms to substance abuse issues, providing the most comprehensive and effective care.

Emotional and social support is crucial in the treatment of co-occurring disorders. Such support can improve the person's motivation to engage in treatment, help them build resilience, and provide a sense of belonging. Support can come from various sources, including family, friends, peer support groups, and mental health professionals.

Treatment programs are tailored to the individual's unique needs, but generally, they incorporate a mix of cognitive-behavioral therapy, motivational interviewing, and relapse prevention therapies. These are complemented by medical treatments, life skills training, and social support networks to provide a comprehensive approach to recovery.

Han B, Compton WM, Blanco C, Colpe LJ. Prevalence, Treatment, And Unmet Treatment Needs Of US Adults With Mental Health And Substance Use Disorders. Health Aff Proj Hope. 2017;36(10):1739-1747. doi:10.1377/hlthaff.2017.0584

“Co-occurring Disorders.” Substance Abuse and Mental Health Services Administration, U.S. Department of Health and Human Services, n.d., Accessed 11 July 2023.

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Written By: Linda Whiteside

Licensed Clinical Professional Counselor who has been providing mental health services for over 10 years.

Medically reviewed by: Dr. Ryan Peterson

Went to medical school at The George Washington University School of Medicine in Washington, D.C.

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