"Co-occurring disorders" is the term used to describe the condition of individuals with both an Axis I major mental disorder (e.g., psychotic, depressive, or bipolar) and a substance use disorder, as defined by the Diagnostic and Statistical Manual of Mental Disorders, IV Edition Text Revision (DSM-IV-TR).

Given the increasing incidence of mental illness and/or substance abuse in individuals who are also living with HIV, have criminal justice issues, and/or are homeless, greater attention needs to be provided to the complex of patients' signs and symptoms and related issues, rather than simply treating the disorder that lies within our specialty. Improving the fragmented, uncoordinated healthcare systems in our communities means working in collaborative, multidisciplinary, and cross-trained teams.