Dual diagnosis of substance abuse and severe mental illness: The scope of the problem

Mental illness and substance use co-occur at an alarmingly high rate. Causes of this comorbidity may include self-medication, genetic vulnerability, environment or lifestyle, underlying shared origins, and/or a common neural substrate. The consequences of dual diagnosis include poor medication compliance, physical comorbidities and poor health, poor self-care, increased suicide risk or aggression, increased sexual behavior, and a higher risk of incarceration. Appropriate screening, assessment, and integrated (mental health and addiction) services for dual diagnosis are key components of care for this complex patient group.