Integrated Dual Disorder Treatment

The Integrated Dual Disorder Treatment (IDDT) model is an evidence-based practice that improves quality of life 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 through 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.

Making the Case

Contact us for IDDT technical assistance (fidelity evaluation, consulting and training). 
Integrated Dual Disorder Treatment (IDDT) is multidisciplinary and combines pharmacological (medication), psychological, educational, and social interventions to address the needs of clients and their family members. IDDT also promotes client and family involvement in service delivery, stable housing as a necessary condition for recovery, and employment as an expectation for many.

IDDT reduces

  • Relapse of substance abuse and mental illness
  • Hospitalization
  • Arrest
  • Incarceration
  • Duplication of services
  • Service costs
  • Utilization of high-cost services

IDDT increases

  • Continuity of care
  • Consumer quality-of-life outcomes
  • Stable housing
  • Independent living

Need for Systems Change

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 (alcohol or other drugs) during their lifetimes (see Regier in the "Sources" section on this page).

Separate Services

Historically, people with co-occurring disorders have been excluded from mental health treatment because of their substance use disorders. Likewise, they have been excluded from substance abuse treatment because of their severe mental health symptoms. As a result, they frequently have not gotten the help they need.

Negative Life Outcomes

Individuals with co-occurring disorders are more likely to experience

  • Psychiatric episodes
  • Use, abuse, and relapse to alcohol and other drugs
  • Hospitalization and emergency room visits
  • Relationship difficulties
  • Violence
  • Suicide
  • Arrest and incarceration
  • Unemployment
  • Homelessness
  • Poverty
  • Infectious diseases, such as HIV, hepatitis, and sexually transmitted diseases
  • Complications resulting from chronic illnesses such as diabetes and cancer

To address these negative outcomes, IDDT is often integrated with Assertive Community Treatment (ACT).

Core Components

IDDT promotes recovery among people with co-occurring disorders by providing service organizations with specific strategies for delivering services. The implementation of integrated treatment facilitates service system change, organizational change, and clinical change. IDDT is built upon the following core treatment components:

  • Multidisciplinary Team
  • Stage-Wise Interventions (stages of change, stages of treatment)
  • Access to Comprehensive Services (e.g., residential, employment, etc.)
  • Time-Unlimited Services
  • Assertive Outreach
  • Motivational Interventions
  • Substance Abuse Counseling
  • Group Treatment
  • Family Psychoeducation
  • Participation in Alcohol and Drug Self-Help Groups
  • Pharmacological Treatment
  • Interventions to Promote Health
  • Secondary Interventions for Treatment of Non- Responders

Fidelity and Outcomes

There are treatment characteristics (components) and organizational characteristics of the IDDT model that are called fidelity domains. These domains encourage service systems and organizations to develop holistic integrated program structures and treatments. These domains also provide a structure for a continuous quality-improvement process that addresses multiple outcomes.

IDDT facilitates systems change, organizational change, and clinical change when it is implemented with fidelity. Research shows that organizations which maintain fidelity to the original design of IDDT achieve and sustain the best outcomes. IDDT has a fidelity scale that helps organizations implement and sustain the model.

Integrated Dual Disorder Treatment for Inpatient Settings

Integrated Dual Disorder Treatment (IDDT) for Inpatient Settings was developed by the Ohio Substance Abuse and Mental Illness Coordinating Center of Excellence (CCOE)—an initiative of the Center for Evidence-Based Practices at Case Western Reserve University—and the State of Ohio’s inpatient Behavioral Healthcare Organizations (BHOs). This model was created with reference to and as an adaptation of the community-based IDDT model and fidelity scale.

The IDDT model is an evidence-based practice that improves the quality of life 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.

The Lynn Goff Spirit of Integrated Treatment Award

For many years, the CEBP awarded IDDT service teams that embodied passion, dedication, and creativity with the Lynn Goff Spirit of Integrated Treatment Award. It recognizes those who consistently go above and beyond the expectations of the Integrated Dual Disorder Treatment (IDDT) model and, in doing so, raise the standard for exceptional care. The award is given in memory of Lynn Goff, whose life and daily work in Fayette and Highland Counties, Ohio, embodied the principles of the IDDT model.

Read more about Lynn Goff and the award in her honor.

Research and Development

  • Integrated Dual Disorder Treatment (IDDT), the evidence-based practice, was developed and continues to be studied by researchers at the Dartmouth Psychiatric Research Center of Dartmouth Medical School in Lebanon, New Hampshire. The researchers include Robert E. Drake, MD, PhD; Kim T. Mueser, PhD; and their colleagues.
  • The Dartmouth PRC has provided leadership for national implementation of IDDT via the Substance Abuse and Mental Health Services Administration. The State of Ohio and the Center for Evidence-Based Practices at Case Western Reserve University—through its Ohio  SAMI Coordinating Center of Excellence (CCOE)—participate in these national initiatives, making significant contributions to the advancement and enhancement of the IDDT model.

Resources and Tools

The Center for Evidence-Based Practices has developed a number of resources to help with the implementation of Integrated Dual Disorder Treatment, including CEBP-produced posters, guides, booklets, scales, and indexes, as well as additional articles, websites, recommended SAMHSA tools, and recommendations for further reading.

Explore all of our resources

Related Stories