Research on substance abuse treatment outcomes has shown that program and organizational characteristics, in addition to patient attributes, are related to treatment outcomes (60
). Our study contributes to this growing area of research by identifying several programmatic attributes that are associated with improved outcomes among individuals with co-occurring disorders. Specifically, patients treated in residential substance abuse programs that provided on-site dual diagnosis groups and that had more counselors trained in treatment of co-occurring disorders had higher rates of utilizing mental health services, which in turn predicted greater improvements in mental health status and reductions in heroin use after treatment. Patients treated in programs with more on-site mental health services also spent more time in treatment, which was similarly related to higher rates of service use and improved outcomes.
This study was conducted with publicly funded substance abuse treatment programs within one urban county. This contrasts with previous research on treatment for patients with co-occurring disorders, which has often focused on highly specialized programs, such as those for veterans or demonstration studies of innovative or enhanced programs. Furthermore, the programs in this study varied in the degree to which they provided an environment consistent with the concept of a dual diagnosis treatment orientation as described by Moos and colleagues (28
). Although the overall study findings may be limited in generalizability to the unique characteristics of the treatment system within the county we studied, the programs showed sufficient variability to enable us to differentiate relationships between program-level attributes and patient outcomes.
In contrast with the variability in service profiles among the study programs, patients in this sample were relatively homogeneous with regard to prior treatment history, perceived quality of life, motivation for treatment, and socioeconomic status (49
). We attribute this homogeneity to the relatively high threshold of severity that is typically required for admission to residential treatment (61
). Thus some variables that may normally differentiate treatment outcomes were not included in our model because of a lack of variability within this sample.
A noteworthy exception to this homogeneity is the finding that African Americans had greater levels of psychological distress both before and after treatment, yet were less likely to be treated in programs that provided on-site mental health services. This finding concurs with other recent research showing higher levels of psychiatric symptoms among nonwhite patients in treatment for co-occurring disorders and yet less access to appropriate services (62
) and generally greater unmet needs for mental health services (63
). Moreover, it suggests that African Americans with co-occurring disorders face additional obstacles to obtaining mental health services; future research needs to address strategies for delivering services to this population, including whether culturally competent interventions can improve use of needed services (67
Although the time frame for patient- and program-level data collection overlapped, the program characteristics reflected in the administrator surveys may have changed over the period when patients received treatment from these programs. Yet all programs were relatively stable in funding and operation over the period of study, and we have no reason to suspect a history effect on the basis of our observations. Also, interpretation of findings should consider that the predictive model does not differentiate between psychological services utilized by patients in the initial substance abuse treatment episode and those received in aftercare or elsewhere in the community. We note that patients averaged 93 days in treatment and that fewer than 5 percent were still in residential treatment at the time of the follow-up assessment. Moreover, our intent was to examine whether certain program characteristics facilitated use of services, either through the provision of on-site services or collaboration with other service providers. Last, because we sampled a subgroup of patients from the study programs (those who met the study inclusion criteria over the study recruitment period) and hence did not collect data from all other patients in these programs, we were unable to describe how the study sample differed from the patients who were treated within these programs.