Medically Reviewed By

Brittany Kowalski, LCSW, ACS, CCS

Clinical Director, Speranza Behavioral Health · Last clinically reviewed June 2026

What Is Dual Diagnosis? Understanding Co-Occurring Disorders in Addiction Treatment

If you've heard the term dual diagnosis and wondered what it means — or if it applies to you or someone you love — you're in the right place. Dual diagnosis is one of the most important concepts in behavioral health, and understanding it can completely change the way you approach treatment.

In simple terms, dual diagnosis means that a person is living with both a substance use disorder and a mental health condition at the same time. This combination — also called co-occurring disorders — is not rare. In fact, it's the norm rather than the exception in addiction treatment.

How Common Are Co-Occurring Disorders?

The numbers are striking:

• According to SAMHSA, approximately 17 million adults in the United States have both a substance use disorder and a mental health condition
• Nearly 50% of people with a severe mental illness also experience a substance use disorder
• More than 60% of people in addiction treatment have a diagnosable co-occurring mental health condition
• People with anxiety disorders are nearly 3x more likely to have an alcohol use disorder
• Depression is the most commonly co-occurring mental health condition with substance use disorders

Despite how prevalent co-occurring disorders are, the majority of people with dual diagnosis receive treatment for only one condition — if they receive treatment at all.

Which Mental Health Conditions Most Commonly Co-Occur With Addiction?

Depression and Substance Use Disorder

Depression and addiction have a deeply intertwined relationship. People with untreated depression may use alcohol or drugs to self-medicate — temporarily lifting their mood before creating a deeper biochemical depression. Conversely, chronic substance use depletes dopamine and serotonin systems, directly causing or worsening depressive episodes. Learn more about depression treatment →

Anxiety Disorders and Substance Use Disorder

Alcohol is one of the most commonly used substances to manage anxiety — it provides temporary relief by activating GABA receptors. But over time, alcohol worsens baseline anxiety significantly, creating a cycle of dependence and escalating anxiety. Benzodiazepine dependence often develops in the same way — prescribed for anxiety, escalating into dependence.

PTSD and Substance Use Disorder

PTSD and addiction are among the most common co-occurring pairs in behavioral health. Research indicates that 30–59% of people seeking addiction treatment also meet criteria for PTSD. Many people with undiagnosed or untreated trauma use substances to numb intrusive memories, hypervigilance, or emotional overwhelm. Read about PTSD treatment →

Bipolar Disorder and Substance Use Disorder

Bipolar disorder has one of the highest rates of co-occurring substance use disorder — with some studies showing that more than 50% of people with bipolar disorder will develop a substance use disorder in their lifetime. The mania and impulsivity of bipolar disorder increase risk-taking behaviors including substance use, while substances destabilize mood cycles.

ADHD and Substance Use Disorder

Untreated ADHD in both adolescents and adults is a significant risk factor for substance use disorder. People with ADHD may use stimulants, cannabis, or alcohol to manage attention difficulties, impulsivity, or emotional dysregulation.

Borderline Personality Disorder (BPD) and Substance Use

BPD, characterized by emotional dysregulation, impulsivity, and unstable relationships, frequently co-occurs with substance use as a mechanism of emotional coping. Dialectical Behavior Therapy (DBT) — which Speranza uses as a core treatment modality — was specifically designed to treat BPD and is highly effective for co-occurring BPD and addiction.

Which Came First: The Addiction or the Mental Health Condition?

This is one of the most frequently asked questions about co-occurring disorders — and the honest answer is that it varies, and it often doesn't matter as much as people think.

Three common patterns:

1. Mental health first — A person develops depression, anxiety, PTSD, or another condition, and begins using substances to self-medicate. The substance use escalates into dependence.

2. Substance use first — Prolonged substance use chemically alters brain function in ways that produce anxiety, depression, paranoia, or mood instability.

3. Parallel development — Both conditions develop simultaneously, influenced by shared genetic, neurological, and environmental factors.

Regardless of which came first, both conditions must be treated simultaneously for recovery to last.

Why Treating Only One Condition Fails

This is the critical insight that changed how the behavioral health field approaches treatment:

If you treat the addiction but not the underlying mental health condition, the mental health condition will drive relapse.

If you treat the mental health condition but not the addiction, the addiction will undermine the mental health treatment.

For decades, addiction and mental health were treated as separate systems — addiction by one type of clinician, mental health by another. Research now unambiguously shows that integrated, simultaneous treatment produces significantly better outcomes than sequential or parallel treatment.

What Does Dual Diagnosis Treatment Look Like at Speranza?

At Speranza Behavioral Health in Woodbury, NJ, dual diagnosis treatment is not an add-on — it's the foundation of our clinical model. Our approach includes:

• Comprehensive psychiatric assessment at intake to identify all co-occurring conditions
• Integrated therapy — CBT, DBT, EMDR, and trauma-focused modalities that address both addiction and mental health simultaneously
• Psychiatric medication management — when appropriate, medications to stabilize mood, anxiety, or PTSD symptoms support the recovery process
• Trauma-informed care throughout every level of treatment
• Specialized group therapy tracks for depression/anxiety, trauma/PTSD, and mood disorders within our PHP and IOP programs
• Relapse prevention planning that addresses mental health triggers and coping strategies

Getting a Dual Diagnosis Assessment in South Jersey

If you suspect that you or a loved one may be dealing with both addiction and a mental health condition, the right first step is a comprehensive clinical assessment. At Speranza Behavioral Health, we provide free, confidential assessments — usually able to begin the same day you call.

Call (866) 814-0126 — our team serves all of South Jersey including Gloucester County, Camden County, Burlington County, Atlantic County, and beyond.

Learn about our dual diagnosis programs →

Related Reading:

• The Connection Between Mental Health and Substance Abuse
• Effects of Untreated Trauma and How to Seek Help
• The Signs and Symptoms of Clinical Depression

About the Author

Brittany Kowalski

Brittany Kowalski is a licensed clinical social worker (LCSW) and behavioral health advocate at Speranza Behavioral Health in Woodbury, NJ. With over a decade of experience in addiction recovery and mental health treatment, she specializes in dual diagnosis care, trauma-informed therapy, and evidence-based outpatient programs serving South Jersey communities.