Integrated dual diagnosis treatment among United States mental health treatment facilities: 2010 to 2018

•The proportion of facilities that reported offering any substance use services increased from 50.1% in 2010 to 57.1% in 2018.•Among facilities with substance use services, significantly fewer facilities reported Integrated Dual Diagnosis Treatment in 2018 than in 2010•State facility licensing and state implementation of Integrated Dual Diagnosis Treatment are linked to more common use of this model. Little is known about the correlates of and recent trends in implementation of Integrated Dual Diagnosis model, an evidence-based approach for dual diagnosis services, in US mental health facilities between 2010 and 2018. Changes over time in Integrated Dual Diagnosis Treatment use were examined using multiple waves of a national survey of mental health treatment facilities that reported offering any substance use services. State and facility correlates of offering integrated dual diagnosis services among these facilities in 2018 were examined. The proportion of mental health treatment facilities that reported offering any substance use services increased significantly from 50.1% in 2010 to 57.1% in 2018. Among these facilities, significantly fewer reported offering Integrated Dual Diagnosis Treatment in 2018 (74.8%) than in 2010 (79.6%). The prevalence of Integrated Dual Diagnosis Treatment use increased in more recent years in tandem with increase in substance use services, though the increases in Integrated Dual Diagnosis Treatment have not matched the expansion of substance use services. Mental health facilities with substance use services more commonly offered other mental health services and had more funding sources available. Facilities with any substance use disorder services that offered Integrated Dual Diagnosis Treatment were more commonly licensed by State Substance Agencies and more commonly offered psychotropics and group therapies. Facilities located in states that implemented the Integrated Dual Diagnosis Treatment model had a higher odds of offering this model. The growth in the co-location of substance use treatment services within mental health treatment facilities has not been matched by true integration of these treatments, highlighting the need for further efforts to comprehensively address the complex needs of dually diagnosed patients.