Co-occurring mental illness in emergency department and hospital inpatient encounters related to substance abuse in Maryland

Background Mental illness and substance abuse are highly comorbid conditions. At the individual level, symptoms of one can influence symptoms of the other and therefore demand treatment approaches specific to the combination of substance abused and mental illness. At the population level, co-occurring substance use and mental illness challenge public health prevention efforts and decrease treatment system effectiveness. However, due to the scarcity of integrated data, there has not been a thorough understanding of co-occurrence of substance use and mental illness. This study examines prevalence and trends of mental illness among substance abuse-related emergency department (ED) and hospital inpatient encounters.