Addiction treatment services and co-occurring disorders: the ASAM-PPC-2R taxonomy of program dual diagnosis capability.

Background: The ASAM-PPC-2R taxonomy of addiction treatment program dual diagnosis capability provides a conceptual model of services for persons with co-occurring substance use and psychiatric disorders. However, no objective study of this model has been conducted.
Method: This paper describes a survey of addiction treatment providers (n = 453) who were asked to identify their program as Addiction Only Services (AOS), Dual Diagnosis Capable (DDC) or Dual Diagnosis Enhanced (DDE). The survey also queried providers on prevalence estimates, clinical practices, and perceived barriers to treating persons with co-occurring substance use and psychiatric disorders.
Results: With brief definitions available to respondents, 92.9% of providers surveyed categorized their program as: AOS (23.0%), DDC (65.3%) or DDE (11.6%). Patient characteristics, clinical practices, and barriers to effective treatments varied by program dual diagnosis capability.
Conclusions: The findings support the utility of the ASAM dual diagnosis capability taxonomy, and suggest specific avenues for system and program assessment and future research.