Research consistently shows a high prevalence of suicidal thoughts and suicide attempts among persons with substance abuse problems who are in treatment (Ilgen, Harris, Moos, & Tiet, 2007) and a significant prevalence of death-by-suicide among those who have at one time been in substance abuse treatment when compared with those who do not have a diagnosis of substance use disorder (Wilcox et al., 2004). As a result, substance abuse treatment providers must be prepared to gather information routinely from, refer, and participate in the treatment of clients at risk for suicidal behavior. Suicidal thoughts and behaviors are also a significant indicator of other co-occurring disorders (such as major depression, bipolar disorder, PTSD, schizophrenia, and some personality disorders) that will need to be explored, diagnosed, and addressed to improve outcomes of substance abuse treatment.