Co-Occuring Meaning in Dual Diagnosis Care

If you are reading a chart note, a rehab recommendation, or an insurance summary and you see the word co-occuring (more commonly spelled co-occurring), it can feel intimidating. It also matters more than it sounds. In addiction treatment, that single term often signals that substance use and mental health are intertwined, and that recovery usually goes better when both are treated together.

This guide explains what co-occuring means in plain English, why it is so common, how to recognize the signs of a possible co-occurring disorder, and what integrated dual diagnosis treatment typically looks like.

Important: If you or someone you love is in immediate danger, experiencing suicidal thoughts, or showing signs of overdose, call 988 (Suicide and Crisis Lifeline in the US), call 911, or go to the nearest emergency room.

What does co-occuring mean?

Co-occuring means two conditions are happening at the same time in the same person.

In addiction and behavioral health, co-occuring most often refers to:

• A substance use disorder (SUD) (such as alcohol use disorder or opioid use disorder)
• A mental health condition (such as depression, anxiety, PTSD, bipolar disorder, or psychotic disorders)

This is frequently called co-occurring disorders or dual diagnosis.

Even though the spelling “co-occuring” is common online, the standard clinical spelling is co-occurring (with a hyphen and two “r”s). In real-world searches and documentation, people use both.

Co-occurring disorders vs dual diagnosis

These terms are closely related, and people often use them interchangeably, but there is a subtle difference:

• Dual diagnosis usually implies one SUD plus one mental health disorder.
• Co-occurring disorders can mean the same thing, but it can also include more than two conditions (for example, opioid use disorder plus PTSD plus depression).

Comorbidity vs co-occuring

You might also hear the word comorbidity. It is a broader medical term meaning more than one diagnosable condition exists at the same time.

In many healthcare settings:

• Comorbidity can refer to any combination of conditions (diabetes and high blood pressure, asthma and anxiety, chronic pain and depression).
• Co-occurring is frequently used in behavioral health to highlight the way mental health and substance use interact, and why they should be treated together.

How common are co-occurring disorders?

Co-occurring disorders are not rare, and you are not alone if this is part of your story.

According to SAMHSA, based on the 2024 National Survey on Drug Use and Health (NSDUH), approximately 21.2 million adults in the US had a co-occurring mental illness and substance use disorder.

Source: SAMHSA – Co-Occurring Disorders and Other Health Conditions.

Why co-occuring conditions matter in addiction recovery

When mental health symptoms and substance use are happening together, they can create a loop that is hard to break without the right support.

How one condition can fuel the other

• Self-medication: Someone drinks to “turn off” anxiety, uses opioids to numb grief, or uses stimulants to push through depression.
• Substance-induced mental health symptoms: Alcohol can worsen depression and sleep. Stimulants can trigger panic, paranoia, or psychosis. Cannabis can worsen anxiety or trigger panic in some people. (If alcohol is involved, see: how alcohol can change behavior and judgment.)
• Shared risk factors: Genetics, trauma exposure, chronic stress, unstable housing, and lack of access to care can increase risk for both mental health conditions and SUD.

When treatment focuses on only one side, people may feel like they are failing because symptoms keep returning. In reality, it often means the plan is incomplete.

Common examples of co-occurring disorders

Co-occuring does not point to one specific pairing. It can include many combinations. Common examples include:

• Alcohol use disorder + depression
• Alcohol use disorder + anxiety disorders
• Opioid use disorder + PTSD
• Methamphetamine use disorder + psychosis symptoms
• Cannabis use disorder + panic disorder
• SUD + bipolar disorder
• SUD + ADHD

There can also be physical health issues that complicate the picture, such as chronic pain, sleep disorders, or infectious disease risk, especially for people who inject drugs. Those may not be “co-occurring disorders” in the strict behavioral-health sense, but they still matter clinically.

Signs addiction and mental health may be co-occuring

Only a qualified clinician can diagnose a substance use disorder or a mental health disorder. Still, certain patterns can suggest that dual diagnosis assessment is important.

Possible signs in day-to-day life

• Using substances to manage panic, intrusive thoughts, trauma memories, or insomnia
• Repeated relapse after short periods of sobriety, especially when mental health symptoms remain untreated
• Ongoing depression, irritability, or mood swings that persist even during abstinence
• Substance use that escalates after major stressors (loss, breakup, job stress, conflict)
• Difficulty functioning in work, school, or relationships due to both emotional symptoms and substance-related consequences
• A history of trauma, self-harm, psychiatric hospitalization, or suicidal thoughts

When to treat this as urgent

Seek emergency help right away if someone is:

• Having suicidal thoughts or has a plan to harm themselves
• Experiencing hallucinations, severe paranoia, or not sleeping for days
• At risk of severe withdrawal (especially from alcohol or benzodiazepines)
• Showing signs of overdose or repeatedly using alone (families can learn practical steps in this guide to responding to opioid overdoses)

Which comes first: mental health or substance use?

This is one of the most common questions people ask, and it is also one of the reasons co-occurring disorders can be complex.

There are a few common paths:

1. Mental health symptoms come first – someone begins using substances to cope (self-medication).
2. Substance use comes first – ongoing use triggers or worsens mood, anxiety, or psychosis symptoms.
3. They develop together – shared risk factors and life circumstances contribute to both.

In real life, it is often not a clean timeline. People can also have a mental health disorder that is real and longstanding, plus additional symptoms that are substance-induced. A good assessment is meant to sort that out without judgment.

How co-occurring disorders are diagnosed

A solid dual diagnosis evaluation usually includes both medical and behavioral health questions, such as:

• Substance use history: what substances, how often, how much, route of use, overdose history, withdrawal history
• Mental health screening: depression, anxiety, PTSD, bipolar disorder, psychosis, ADHD
• Medical assessment: sleep issues, pain, current medications, chronic conditions
• Timeline mapping: when symptoms started relative to substance use
• Safety planning: overdose risk, suicidal thinking, self-harm risk, domestic violence risk

Because substances can strongly affect sleep, mood, and thinking, clinicians often reassess symptoms after stabilization. That does not mean you have to wait to get support. It means the diagnosis may be refined as the body and brain recover.

What integrated treatment looks like for co-occuring disorders

Integrated treatment means the treatment plan addresses both substance use and mental health at the same time, ideally with coordinated providers who communicate with each other.

It can happen in inpatient rehab, residential treatment, intensive outpatient (IOP), outpatient therapy, and medication-based treatment settings. For a practical overview of what programs typically offer, see what rehab facilities do and how they help.

Core parts of dual diagnosis care

• Withdrawal management and detox when needed, especially for alcohol, benzodiazepines, or heavy opioid use
• Medication for substance use disorder when appropriate (for example, medications for opioid use disorder or alcohol use disorder)
• Psychiatric evaluation for depression, anxiety, PTSD, bipolar disorder, psychotic disorders, and sleep disorders
• Evidence-based therapy that supports both conditions, such as CBT, DBT, motivational interviewing, and trauma-informed care
• Relapse prevention planning with practical coping skills, trigger management, and recovery routines
• Family support when safe and desired, since loved ones are often affected and can be part of healing
• Aftercare planning including peer support, ongoing therapy, medication follow-up, and crisis plans

Trauma treatment timing matters

Many people with co-occuring disorders have trauma histories. Trauma-focused therapy can be life-changing, but timing and pacing are important. Early recovery sometimes starts with stabilization first (sleep, safety, cravings, emotional regulation) before deep trauma processing.

[VIDEO: What trauma-informed addiction treatment means]

Common treatment pitfalls to avoid

1. Treating only the addiction

If anxiety, PTSD, or depression is driving cravings, simply stopping substance use without mental health support can feel unbearable. That often leads to relapse, not because someone is weak, but because their nervous system is still in distress.

2. Treating only the mental health symptoms

If a person is actively using, therapy and medication may not work as intended. Substance use can also increase risks with certain prescriptions. For example, SAMHSA warns that combining medications used to treat SUD with certain anxiety medications like benzodiazepines can have serious adverse effects.

3. Assuming symptoms are “just withdrawal” or “just mental illness”

Sometimes symptoms improve dramatically with sobriety. Sometimes they do not, because there is an underlying mental health condition that needs treatment. Good care stays curious, tracks symptoms over time, and adjusts the plan.

What to look for in a co-occuring disorders program

If you are calling programs or providers, consider asking questions like:

• Do you offer integrated treatment for mental health and substance use?
• Can I see a psychiatrist or psychiatric nurse practitioner if needed?
• What therapies do you use for dual diagnosis (CBT, DBT, trauma-informed approaches)?
• How do you handle medication management and potential interactions?
• Do you offer aftercare planning and coordination with outpatient providers?
• How do you support families and loved ones?

[VIDEO: Questions to ask a dual diagnosis rehab or therapist]

What you can do today if you think issues are co-occuring

If you are overwhelmed, you do not have to solve everything at once. These steps can help you move forward without needing perfect clarity on day one:

1. Write down the basics – substances used, frequency, last use, sleep, mood symptoms, panic episodes, traumatic triggers, and any safety concerns.
2. Ask for a dual diagnosis assessment – use the words “co-occurring disorders” or “integrated treatment.”
3. Be honest about withdrawal risk – especially alcohol and benzodiazepines. Detox can be a safety issue, not a willpower issue.
4. Plan for overdose prevention – if opioids are involved, ask about naloxone and safer-use strategies while you seek treatment. (Families can review overdose response basics here: how to respond to opioid overdoses.)
5. Build follow-up support – therapy, medication follow-up, peer support, and a crisis plan are part of recovery, not optional extras.

Related reading on Drug Addiction Now

• What rehab facilities do and how they help
• Rehab for couples and how partners can heal together
• How families can respond to opioid overdoses

More support (our network)

• What a halfway house is and how transitional recovery housing helps (ADR)
• Am I an alcoholic? Signs to consider and next steps (ADR)
• Find mental health support in San Francisco, California (ALT)