Understanding the Term: What term co-occurring disorders replaces the term?

October 1, 2025 •

4 min read

According to the Substance Abuse and Mental Health Services Administration (SAMHSA), approximately 21.5 million adults experienced both a mental health condition and a substance use disorder in 2022. The modern, preferred term for this is 'co-occurring disorders', which specifically replaces the outdated and often misleading phrase 'dual diagnosis'. The move towards this more accurate terminology reflects a deeper understanding of the complex interplay between mental illness and substance use.

Quick Summary

The term 'dual diagnosis' was replaced by 'co-occurring disorders' to more accurately reflect that an individual can have multiple co-existing mental and substance use disorders, not just two. This change in terminology emphasizes the complexity of these conditions and the need for comprehensive, integrated treatment that addresses all diagnoses simultaneously for better long-term recovery.

Key Points

The Term Replaced: The term 'co-occurring disorders' replaced the older term 'dual diagnosis' to more accurately describe co-existing mental and substance use disorders.
Complexity of Conditions: The new terminology acknowledges that individuals may have more than two co-existing disorders, not just a 'dual' combination, representing a more inclusive view.
Integrated Treatment: The shift in language is paired with a move towards integrated care, where all conditions are treated simultaneously by the same clinical team for better outcomes.
Reduces Stigma: Using 'co-occurring disorders' and person-first language helps reduce the stigma associated with these conditions, encouraging more people to seek help without judgment.
Standard of Care: Integrated treatment is now the recommended standard of care, leading to reduced substance use, improved psychiatric symptoms, and decreased hospitalization rates.
Holistic Approach: Integrated care provides a cohesive, seamless treatment experience for individuals, avoiding the pitfalls of older, fragmented approaches.

The Shift in Terminology: From 'Dual Diagnosis' to 'Co-occurring Disorders'

For many years, the term 'dual diagnosis' was the standard terminology used to describe the presence of both a substance use disorder (SUD) and a mental health disorder in the same individual. While intended to acknowledge the complex nature of these intertwined conditions, the term was recognized as being limiting and potentially inaccurate. The word 'dual' implies only two conditions, yet many individuals experience more than one mental health disorder alongside an SUD. The evolution of clinical understanding led to the adoption of 'co-occurring disorders' as the standard term, a more inclusive phrase that acknowledges the possibility of multiple coexisting conditions.

This shift wasn't just about semantics; it reflected a major change in the approach to treatment. Historically, the mental health and substance abuse treatment fields operated in separate silos. A person seeking help for addiction might be told to get sober before addressing their mental health, or vice versa, an approach with a low success rate. The adoption of 'co-occurring disorders' coincided with a move toward integrated treatment, where both conditions are addressed simultaneously by the same clinical team.

The Meaning and Scope of Co-occurring Disorders

A co-occurring disorder, as defined by SAMHSA, is the simultaneous existence of both a substance use disorder and a mental health disorder. This can include any combination of disorders, from anxiety and depression alongside alcohol or opioid use disorders, to more severe mental illnesses like schizophrenia or bipolar disorder. The relationship between these conditions is complex and bidirectional. Some individuals may use substances to self-medicate for mental health symptoms, while chronic substance use can alter brain chemistry and trigger or worsen mental health problems.

Key Distinctions: Comorbidity vs. Co-occurring Disorders

While often used interchangeably in general conversation, comorbidity is a broader medical term for any two or more health conditions occurring in the same person. The presence of diabetes and heart disease, for instance, is a form of comorbidity. Co-occurring disorders, however, specifically refers to the combination of a mental health disorder and a substance use disorder. This precision is important because it highlights the specialized and integrated approach required for effective treatment. A person with a medical and mental health comorbidity might see separate specialists, but for co-occurring mental health and substance use disorders, an integrated care team is the standard of care for the best outcomes.

Why Terminology Matters for Treatment

Beyond accuracy, the language used to describe these conditions directly impacts the experience of individuals seeking help. The term 'dual diagnosis' often carried a significant amount of stigma. The shift to 'co-occurring disorders' helps to normalize the experience, framing it not as a special or rare condition, but as a prevalent and treatable reality. Using person-first language, such as 'a person with a co-occurring disorder,' also helps reduce stigma by focusing on the individual rather than defining them by their illness. This shift in perspective is crucial for encouraging individuals to seek help without fear of judgment, leading to better engagement and retention in treatment.

Understanding the Integrated Treatment Approach

Integrated treatment is an evidence-based practice that addresses co-occurring mental health and substance use disorders in a coordinated, simultaneous fashion. This approach is in stark contrast to older, sequential treatment models that often failed patients with co-occurring conditions. The National Institute on Drug Abuse (NIDA) highlights that research consistently shows that integrated treatment leads to better outcomes and a higher quality of life.

Benefits of Integrated Treatment

Holistic Care: The same team of providers addresses both mental health and substance use, avoiding fragmented care and mixed messages.
Better Outcomes: Studies show that integrated care leads to reduced substance use, improved psychiatric symptoms, and overall increased functioning.
Sustained Recovery: By treating the root causes and triggers of both conditions, patients have a higher chance of achieving long-term recovery.
Reduced Hospitalization: Effective integrated care can lead to fewer hospitalizations and emergency visits.
Increased Housing Stability: Addressing all underlying issues improves stability in various aspects of life, including housing.
Cost-Effectiveness: While addressing both issues, integrated treatment has been shown to reduce overall healthcare costs by preventing costly crises.

A Comparison of Treatment Approaches


Feature	Fragmented (Older) Model	Integrated (Modern) Model
Philosophy	Treat mental health and SUD separately and sequentially; prioritize one over the other.	Treat all co-occurring conditions simultaneously and equally.
Provider Network	Different providers and agencies handle different disorders, with little to no communication between them.	One coordinated team of clinicians and providers working together to deliver a single, consistent treatment plan.
Effectiveness	Historically low success rates due to high risk of relapse when one condition is left untreated.	Consistently linked to better outcomes, increased stability, and higher quality of life.
Patient Experience	Confusing and frustrating experience, with patients often falling through the cracks of the separate systems.	Cohesive and seamless experience, with a single point of contact and unified treatment message.

Conclusion: The Path Forward in Integrated Care

The evolution of terminology from 'dual diagnosis' to the more precise and less stigmatizing 'co-occurring disorders' is a testament to progress in the behavioral health field. This change in language reflects a broader shift towards understanding the complex and often bidirectional relationship between mental illness and substance use. Most importantly, it has spurred the adoption of integrated treatment models, which are now considered the gold standard of care. By providing holistic, coordinated treatment that addresses all of a person's conditions at once, healthcare providers can offer more effective and compassionate care, paving the way for more successful and sustainable recovery for millions of individuals. This journey towards recovery is not a single path but a comprehensive, integrated effort that offers hope and better outcomes for those in need.

For more information on integrated treatment, consult the Substance Abuse and Mental Health Services Administration (SAMHSA) website.

Frequently Asked Questions

The term 'co-occurring disorders' is preferred because it is more inclusive and accurate. 'Dual' implies only two conditions, while an individual can have multiple mental health and substance use disorders simultaneously. It also reduces stigma associated with the older term.

'Comorbidity' is a broader term for any two or more health conditions occurring at the same time, whether physical or mental. 'Co-occurring disorders' is a more specific term referring to the co-existence of a mental health disorder and a substance use disorder.

No. While they often influence each other, a co-occurring mental health and substance use disorder does not mean one directly caused the other. Common risk factors like genetics, trauma, and brain chemistry changes can contribute to both.

Integrated treatment is a therapeutic approach where both a mental health disorder and a substance use disorder are treated at the same time by the same clinical team. This holistic method is considered the standard of care for co-occurring conditions.

Co-occurring disorders are very common. According to SAMHSA, millions of adults in the U.S. have a co-occurring disorder, and a large percentage of those with a mental illness also have a substance use problem.

Common combinations include depression or anxiety disorders with alcohol use disorders, PTSD with substance use, and bipolar disorder with substance use.

Yes. Integrated treatment is available in various settings, including outpatient programs, partial hospitalization, and aftercare support, tailored to an individual's specific needs and level of care.

Diagnosing co-occurring disorders can be challenging because the symptoms often overlap, and one condition can mask or exacerbate the other. Comprehensive assessment by a trained professional is necessary for accurate diagnosis.