Dual Diagnosis: When a Mental Disorder and a Substance Use Disorder Occur Together

A dual diagnosis means a person has both a mental disorder and a substance use disorder (SUD), involving alcohol or drugs. It is one kind of comorbidity, two disorders present at the same time, and is also called co-occurring disorders.

How common it is

The two kinds of disorder often go together. Many people who develop an SUD are also diagnosed with a mental disorder, and many people with a mental disorder go on to develop an SUD. Having both is even more common among:

• teenagers;
• people with serious mental illness;
• people with certain mental disorders.

Why they occur together

Appearing together does not mean one caused the other, even when one came first, and which came first can be hard to tell. Researchers see three possible reasons:

1. Shared risk factors can feed both: genetics, stress, and trauma, especially in childhood. Veterans with post-traumatic stress disorder (PTSD) are also at risk for SUDs.
2. Mental disorders can lead to drug use and SUDs. Some people use alcohol or drugs to feel better for a while, which is called self-medication. Mental disorders may also change the brain in ways that make addiction more likely.
3. Substance use and addiction can lead to a mental disorder, by changing the brain in ways that make one more likely.

Treatment

With a dual diagnosis, it usually works better to treat both conditions at the same time rather than one after the other. A health care provider and the patient can build a plan that fits the person, taking into account their age, the substance or substances being misused, and the specific mental disorder or disorders.

A plan may include:

• Behavioral therapy: talk therapy (psychotherapy), long-term residential treatment that combines housing with treatment services, and therapies that help people stay motivated to follow their plan.
• Medicines: effective medicines exist for opioid, alcohol and nicotine addiction, and others ease the symptoms of many mental disorders. Some medicines may treat more than one disorder.
• A referral to a support group: groups offer emotional and social support, and a place to swap tips on handling day-to-day challenges.

Sources

• MedlinePlus, produced by the U.S. National Library of Medicine, "Dual Diagnosis": https://medlineplus.gov/dualdiagnosis.html — drawing on the National Institute on Drug Abuse (NIH).