Assessing the Dual Diagnosis Capability of Addiction Treatment Services: The Dual Diagnosis Capability in Addiction Treatment (DDCAT) Index

Background: Addiction treatment systems and services are increasingly challenged to provide effective treatments for persons with co-occurring disorders. Evidence-based practices are still being developed, and practice benchmarks remain vague in guiding treatment providers in enhancing services, or in delineating standards with which to evaluate the quality of existing care for persons with dual disorders. The American Society of Addiction Medicine (ASAM) proposed a taxonomy of addiction treatment program dual-diagnosis capability, and provided a conceptual model of services for persons with co-occurring substance use and psychiatric disorders. Method: This article describes the development and application of the Dual Diagnosis Capability in Addiction Treatment (DDCAT) Index, which is designed to assess the dual diagnosis capability of addiction treatments services, and is based upon the ASAM taxonomy: Addiction Only Services (AOS), Dual Diagnosis Capable (DDC) or Dual Diagnosis Enhanced (DDE). Results: The DDCAT has been found to have acceptable psychometric properties (internal consistency, inter-rater agreement, kappa) and is sensitive to change. Three case examples illustrate its use in assessing the dual diagnosis capacity of treatment services, and in measuring the targets and impact of change strategies. Conclusions: The DDCAT has demonstrated practical value for addiction treatment systems and treatment service providers. Validity studies are in progress testing the relationship between the index and patient level outcomes.