Co-Occurring Mental and Substance Use Disorders
The coexistence of both a mental illness and a substance use condition is referred to as co-occurring mental and substance use disorders. There are no specific combinations of substance use disorders and mental disorders that are defined uniquely as co-occurring disorders. Co-occurring disorders may include any combination of two or more substance use disorders and mental disorders identified in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). They are also referred to as having a dual diagnosis.
People with a mental health issue are more likely to experience an alcohol or substance use disorder than those not affected by a mental illness. Approximately 7.9 million adults had co-occurring disorders in 2014.
Co-occurring disorders can be difficult to diagnose due to the complexity of symptoms. Both disorders may be severe or mild, or one may be more severe than the other. In many cases, one disorder is addressed while the other disorder remains untreated. Both substance use disorders and mental disorders have biological, psychological, and social components.
There are many consequences of undiagnosed, untreated, or undertreated co-occurring disorders including higher likelihood of experiencing homelessness, incarceration, medical illnesses, suicide, and early death.
Learn more about the treatments available for co-occurring mental and substance use disorders.