Co-Occurring Mental Health and Substance Use Disorders: Signs, Causes & Treatment

“Co-occurring mental health and substance use disorders happen when a person experiences a mental health condition, such as depression, anxiety, PTSD, or bipolar disorder, along with problematic alcohol or drug use. The two conditions can affect each other, making symptoms harder to recognize and manage. Treatment often involves addressing both mental health and substance use concerns through appropriate psychiatric care, therapy, medication when needed, and ongoing support.

Mental health concerns and substance use problems do not always happen separately. A person may be struggling with anxiety while regularly using alcohol to relax, experiencing depression while relying on drugs to cope, or dealing with trauma symptoms alongside problematic substance use.

When a mental health condition and a substance use disorder occur in the same person, they are often described as co-occurring disorders.

The relationship can be complicated. Mental health symptoms may contribute to substance use, while ongoing substance use can worsen emotional or psychiatric symptoms. Sometimes both conditions develop because of shared factors such as trauma, chronic stress, or genetic vulnerability. The National Institute of Mental Health describes this relationship as potentially working in both directions.

Understanding the connection can make it easier to recognize when professional help may be appropriate.

What Are Co-Occurring Mental Health and Substance Use Disorders?

Co-occurring disorders occur when someone has both a mental health disorder and a substance use disorder.

For example, someone may have:

• Depression and alcohol use disorder
• Anxiety and problematic cannabis or stimulant use
• PTSD and opioid use disorder
• Bipolar disorder and alcohol or drug misuse
• Another psychiatric condition alongside problematic substance use

Having one condition does not automatically mean someone has the other. A proper evaluation is needed to understand what is happening and whether symptoms are related to substance use, an independent mental health disorder, or both.

The symptoms can also overlap. Changes in sleep, mood, concentration, motivation, and behavior may occur with both psychiatric conditions and substance use, making an accurate assessment particularly important.

Why Do Mental Health and Substance Use Problems Occur Together?

There is no single explanation.

Using substances to cope

Some people begin using alcohol or drugs because they temporarily reduce distress. Someone with severe anxiety, for example, may drink because it initially makes social situations feel easier. Someone experiencing trauma-related insomnia may use a substance in an attempt to sleep.

The short-term relief can reinforce the behavior even when the longer-term effects become harmful.

Substance use can worsen symptoms

Substance use can also make existing mental health symptoms harder to manage. Changes in sleep, mood, thinking, relationships, and daily functioning may become more pronounced with continued problematic use.

In some situations, substance use can also contribute to psychiatric symptoms. This is one reason clinicians need to understand what substances a person is using, how often they are used, and when symptoms occur.

Shared risk factors

Mental health and substance use disorders can also have overlapping risk factors. Genetics, trauma, chronic stress, environmental circumstances, and other experiences may contribute to both conditions.

This means it is not always useful to ask which problem “caused” the other. Sometimes they develop together through several interacting factors.

Can Substance Use Cause Mental Health Symptoms?

Substance use can contribute to or worsen psychiatric symptoms, but the relationship is not always straightforward.

For example, changes in mood or anxiety may be connected to intoxication, withdrawal, or longer-term substance use. In other cases, a person may already have an underlying mental health condition that becomes more difficult to manage because of substance use.

A clinician may therefore look at the timing of symptoms, periods of substance use and co-occurring mental disorders, previous mental health history, medications, family history, and overall functioning.

A diagnosis made during intoxication or acute withdrawal may sometimes need to be reassessed as the person’s condition stabilizes.

Common Mental Health Conditions That Can Co-Occur with Substance Use

Several mental health conditions can occur alongside substance use disorders.

Depression and substance use

Depression can involve persistent sadness, loss of interest, low motivation, changes in sleep or appetite, difficulty concentrating, and feelings of hopelessness.

Some people may use alcohol or drugs in an attempt to escape these feelings. Unfortunately, continued substance use can make emotional and daily functioning more difficult.

Anxiety and substance use

People with anxiety may use substances to temporarily calm nervousness, worry, panic, or physical tension.

This can create a cycle in which substance use becomes a coping strategy while the underlying anxiety remains untreated.

PTSD and substance use

People experiencing post-traumatic stress disorder may struggle with intrusive memories, avoidance, hyperarousal, sleep problems, or other trauma-related symptoms.

Some may turn to substances in an attempt to numb distress or sleep. Treating the trauma-related symptoms and the substance use problem together may therefore be important.

Bipolar disorder and substance use

Bipolar disorder involves episodes of mood elevation and depression. Substance use can complicate the symptoms and make it more difficult for clinicians to understand changes in mood and behavior.

Because treatment decisions can depend on an accurate understanding of mood episodes, substance use should be discussed openly during psychiatric assessment.

What Are the Signs of Co-Occurring Disorders?

There is no single symptom that proves someone has co-occurring disorders. However, several patterns may justify a professional evaluation.

You may want to seek help if:

• Substance use is becoming difficult to control.
• Alcohol or drugs are being used to manage anxiety, depression, trauma, or sleep.
• Mental health symptoms repeatedly return or become worse after substance use.
• Attempts to stop using substances lead to significant problems.
• Relationships, work, school, or responsibilities are being affected.
• Psychiatric treatment does not seem to be working as expected.
• Relapse repeatedly occurs when emotional symptoms become worse.
• Mood, anxiety, sleep, or thinking changes significantly around periods of substance use.

These signs do not establish a diagnosis. They simply indicate that looking at both mental health and substance use may provide a more complete picture.

How Are Co-Occurring Disorders Diagnosed?

Diagnosis usually starts with a detailed assessment.

A mental health professional may ask about current symptoms, previous diagnoses, medications, substance use, sleep, relationships, work or school functioning, trauma history, and previous treatment.

The timing of symptoms is especially important.

For example, a clinician may need to determine whether depression existed before problematic alcohol use, developed during ongoing use, or continues during periods without alcohol. Similar questions may apply to anxiety, paranoia, mood changes, or sleep disturbances.

The goal is not to assign blame. It is to understand what is happening so treatment can be appropriately planned.

NIMH recommends comprehensive assessment when mental health and substance use disorders may be occurring together because symptoms can overlap.

Why Treating Only One Problem May Not Be Enough

Treating only the most obvious symptom may leave an important part of the problem unaddressed.

For example, someone may receive treatment for anxiety but continue using alcohol to cope with that anxiety. Another person may complete substance use treatment but continue experiencing untreated depression or trauma symptoms.

This does not mean treatment has failed. It may mean that the full clinical picture has not yet been addressed.

Current guidance emphasizes coordinated treatment for people with co-occurring mental health and common comorbidities with substance use disorders. SAMHSA’s 2025 national data report also describes the relationship between the two conditions as bidirectional and notes that treatment approaches may need to address both.

What Does Treatment for Co-Occurring Disorders Involve?

Treatment depends on the individual’s symptoms, diagnosis, substance use, safety needs, medical history, and personal circumstances.

Psychiatric care

A psychiatric evaluation can help identify mental health symptoms and determine whether medication may be appropriate.

Medication is not automatically necessary for everyone. When prescribed, it should be selected and monitored based on the person’s overall clinical situation.

Therapy

Psychotherapy can help people understand emotional triggers, develop healthier coping strategies, manage symptoms, and address behaviors associated with substance use.

Approaches may include cognitive behavioral therapy, motivational interviewing, or other evidence-supported therapies depending on the person’s needs.

Substance use treatment

Some people may need specialized treatment for alcohol or drug use. Treatment can include counseling, behavioral interventions, medications for certain substance use disorders, peer support, or a combination of approaches.

For opioid use disorder and alcohol use disorder, medications may be part of evidence-based treatment when clinically appropriate.

Coordinated care

Integrated care means mental health and substance use concerns are considered together rather than treating each as an unrelated problem.

The appropriate level of care can range from outpatient treatment to more intensive services depending on clinical needs and safety.

When Should You Seek Professional Help?

You do not have to wait until a problem becomes severe before asking for help.

Consider speaking with a mental health professional if substance use is affecting your mood, relationships, work, sleep, or ability to manage everyday responsibilities.

Professional evaluation is particularly important if you are experiencing severe depression, significant mood changes, hallucinations, confusion, withdrawal symptoms, or thoughts of suicide.

If you are in immediate danger or experiencing a life-threatening emergency, call 911. In the United States, you can also call or text 988 for the Suicide & Crisis Lifeline. NIMH recommends 988 for people experiencing a mental health crisis or suicidal thoughts.

What to Expect From a Psychiatric Evaluation

It is normal to feel uncertain about discussing substance use with a mental health professional.

An evaluation is intended to understand your health and determine what type of support may be appropriate. Being honest about alcohol, prescription medications, recreational drugs, and other substances can help the clinician distinguish symptoms and make safer treatment decisions.

You may discuss:

• Your current symptoms
• When symptoms started
• How often they occur
• Substance use patterns
• Previous treatment
• Current medications
• Sleep and daily functioning
• Family and personal mental health history
• Your treatment goals

You do not need to have everything figured out before scheduling an evaluation.

Conclusion

Mental health conditions and substance use disorders can become closely connected. Someone may use substances to cope with emotional symptoms, while ongoing substance use can make those symptoms more difficult to manage. In other cases, both problems may develop from shared risk factors.

The important point is that you do not necessarily have to choose between getting help for mental health symptoms and getting help for substance use. A comprehensive evaluation can help determine whether one or both conditions are present and what type of treatment may be appropriate.

If anxiety, depression, trauma symptoms, mood changes, or substance use are interfering with your life, consider talking with a qualified mental health professional about what you are experiencing. Early evaluation can be an important first step toward understanding the problem and finding appropriate support.

Concerned about co-occurring mental health and substance use symptoms? Schedule a psychiatric evaluation with MyPsychiatryCare to discuss your symptoms, treatment options, and next steps.

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