Concurrent Disorders (also described as dual diagnosis orco-morbitity) describes a condition in which a person has both a mental illness and a substance use problem. This term is a general one that refers to a wide range of mental illnesses and addictions. For example, someone with schizophrenia who is addicted to crack has a concurrent disorder, as does an individual who suffers from chronic depression and who is also an alcoholic. Treatment approaches for each case could be quite different.
People diagnosed with a concurrent disorder generally have shorter life expectancies, are more likely to experience homelessness, have more frequent acute psychiatric admissions, and spend less time in hospital per admission than those without (e.g. either substance use or mental health problems, not co-occurring). Research also suggests that the prognosis of schizophrenia in individuals with a concurrent disorder is considerably more severe than in individuals who have schizophrenia only.
People with concurrent disorders are frequently misdiagnosed, as one disorder can mimic another. Relapse rates for substance use are higher for people with a concurrent mental disorder, as are the chances that symptoms of mental illness will return for those with a concurrent substance use problem.
Mental illnesses and substance use is more prevalent among those experiencing homelessness and those incarcerated than among the general population. Those with concurrent disorders need help and services from several sectors – mental health, addiction, health care, education, and social services. Improving access to the services and supports these individuals need requires a targeted, holistic, multi-disciplinary approach of complementary mental health and addictions services designed to work specifically with concurrent disorders.
Common program elements include comprehensive assessment, intensive case management, supported housing, peer groups for support and therapy, training in independent living skills, and mental health and substance use treatment. Program philosophies typically include acceptance and tolerance of relapses, an emphasis on structured approaches, clear expectations within residential programs, and a commitment to long-term care.