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Integrated Dual Disorder Treatment (IDDT)

Adult Mental Health
  Literature review updated September 2018.

Integrated Dual Disorder Treatment (IDDT) is a specific, integrated approach to treating individuals diagnosed with both serious mental illness and a substance use disorder. This particular model involves multidisciplinary teams composed of case managers, psychologists, psychiatrists or other professionals to manage medication, and a substance abuse counselor. The treatment is provided in an outpatient mental health treatment setting and consists of assertive outreach and a staged approach dependent on the client’s readiness to change. The intervention is designed to be of indefinite duration. Among studies included in this analysis, all participants had a diagnosed substance use disorder and severe mental illness. In two of the included studies, participants were also homeless.

More information on this intervention is available at: http://store.samhsa.gov/product/Integrated-Treatment-for-Co-Occurring-Disorders-Evidence-Based-Practices-EBP-KIT/SMA08-4367.
 
ALL
META-ANALYSIS
CITATIONS

*The effect size for this outcome indicates percentage change, not a standardized mean difference effect size.

Meta-analysis is a statistical method to combine the results from separate studies on a program, policy, or topic to estimate its effect on an outcome. WSIPP systematically evaluates all credible evaluations we can locate on each topic. The outcomes measured are the program impacts measured in the research literature (for example, impacts on crime or educational attainment). Treatment N represents the total number of individuals or units in the treatment group across the included studies.

An effect size (ES) is a standard metric that summarizes the degree to which a program or policy affects a measured outcome. If the effect size is positive, the outcome increases. If the effect size is negative, the outcome decreases. See Estimating Program Effects Using Effect Sizes for additional information on how we estimate effect sizes.

The effect size may be adjusted from the unadjusted effect size estimated in the meta-analysis. Historically, WSIPP adjusted effect sizes to some programs based on the methodological characteristics of the study. For programs reviewed in 2024 or later, we do not make additional adjustments, and we use the unadjusted effect size whenever we run a benefit-cost analysis.

Research shows the magnitude of effects may change over time. For those effect sizes, we estimate outcome-based adjustments, which we apply between the first time ES is estimated and the second time ES is estimated. More details about these adjustments can be found in our Technical Documentation.

Meta-Analysis of Program Effects
Outcomes measured No. of effect sizes Treatment N Effect sizes (ES) and standard errors (SE) Unadjusted effect size (random effects model)
ES SE Age ES p-value
Crime
Any criminal conviction according to court records, sometimes measured through charges, arrests, incarceration, or self-report.
 38 1 123 -0.140 0.138 38 -0.140 0.311
Alcohol use disorder
Clinical diagnosis of alcohol use disorder or symptoms measured on a validated scale.  
 38 1 75 0.165 0.246 40 0.165 0.503
Illicit drug use disorder
Clinical diagnosis of illicit drug use disorder or symptoms measured on a validated scale. When possible, we exclude cannabis/marijuana use disorder from this outcome.
 38 1 45 -0.207 0.304 40 -0.207 0.495
Substance use disorder
A non-specified alcohol or drug use disorder. Typically, a collection of different types of disorders reported by study authors. 
 38 2 105 -0.033 0.345 39 -0.033 0.923
Hospitalization (psychiatric)
Admission to a psychiatric ward or hospital.
 38 1 123 -0.622 0.141 38 -0.622 0.001
Psychiatric symptoms
Mental health symptoms (such as symptoms of psychosis) in individuals with serious mental illness, measured on a validated scale.
 38 2 151 0.049 0.136 40 0.049 0.718
Healthcare costs*
Percent change in total medical costs.
38 1 46 -0.146 0.144 39 -0.146 0.309
Homelessness
A lack of stable housing, often measured through self-report of conditions like living on streets or in shelters in a given time period.
 38 1 46 -0.106 0.205 39 -0.106 0.606

Citations Used in the Meta-Analysis

Drake, R.E., McHugo, G.J., Clark, R.E., Teague, G.B., Xie, H., Miles, K., & Ackerson, T.H. (1998). Assertive community treatment for patients with co-occurring severe mental illness and substance use disorder: A clinical trial. American Journal of Orthopsychiatry, 68(2), 201-215.

Mangrum, L.F., Spence, R.T., & Lopez, M. (2006). Integrated versus parallel treatment of co-occurring psychiatric and substance use disorders. Journal of Substance Abuse Treatment, 30(1), 79-84.

Morse, G.A., Calsyn, R.J., Dean, K.W., Helminiak, T.W., Wolff, N., Drake, R.E., Yonker, R.D., . . . McCudden, S. (2006). Treating homeless clients with severe mental illness and substance use disorders: Costs and outcomes. Community Mental Health Journal, 42(4), 377-404.