Alcohol and other drug problems and mental health disorders often co-exist and are referred to as “co-occurring disorders,” dual diagnosis and co-morbidity. Mental health disorders may precede alcohol and other drug problems or substance use disorders may trigger or exacerbate mental health disorders (NIDA, 2007). In addition to influencing one another, some mental health and substance use disorders have been shown to be caused by common underlying factors (Compton et al., 2007).

Understanding co-occurring disorders is important because they can result in serious consequences to individuals, families, and society as they are prevalent among justice-involved individuals (Tiet and Mausbach, 2007). At midyear 2005, more than half of all prison and jail inmates had a mental health problem (James and Glaze, 2006). Co-occurring disorders may manifest in behaviors that result in probation violations or failures to comply with judicial orders, such as missing meetings. This section provides information to assist justice professionals to recognize these disorders and associated behaviors and how to address them effectively.