The Integrated Dual Disorder Treatment (IDDT) model is an evidence-based practice for people with co-occurring severe mental illness and substance use disorders by combining substance abuse services with mental health services. It helps people address both disorders at the same time—in the same service organization by the same team of treatment providers. IDDT emphasizes that individuals achieve big changes like sobriety, symptom management, and an increase in independent living via a series of small, overlapping, incremental changes that occur over time. Therefore, IDDT takes a stages-of-change approach to treatment, which is individualized to address the unique circumstances of each person’s life. IDDT is multidisciplinary and combines pharmacological (medication), psychological, educational, and social interventions to address the needs of consumers and their family members. IDDT also promotes consumer and family involvement in service delivery, stable housing as a necessary condition for recovery, and employment as an expectation for many. In this project, training, consultation, and fidelity reviews are provided to IDDT programs in the State of Washington.
Research shows that over 50 percent of people in the United States who have been diagnosed with a severe mental illness will also have a diagnosable co-occurring substance use disorder (addiction to alcohol or other drugs) during their lifetimes. Individuals with dual diagnosis constitute a particularly vulnerable subgroup with complex service and treatment needs. These individuals are more susceptible than individuals with a single diagnosis on a host of negative outcomes, including housing instability and hospitalization. IDDT has been shown to reduce relapse of both substance abuse and mental illness, hospitalizations, arrests, incarcerations, duplication of services, and service costs while increasing continuity of care, consumer quality of life outcomes, stable housing, and independent living.