Residential Treatment for Individuals With Substance Use Disorders: Assessing the Evidence

People with substance use disorders have a wide variety of needs across the range of symptom severity. To address these needs, a continuum of care that includes intensive treatment services is in place. Recognition is growing that safe and stable living environments are important in the recovery process for individuals with substance use disorders who need structured care. Residential treatment is a structured, 24-hour level of care that enables a focus on intensive recovery activities. It aims to help people with substance use disorders and a high level of psychosocial needs become stable in their recovery before engagement in outpatient settings and before return to an unsupervised environment, which may otherwise be detrimental to their recovery process. This article describes residential treatment and assesses the evidence base for this service.

This article reports the results of a literature review that was undertaken as part of the Assessing the Evidence Base Series (see box on next page). For purposes of this series, the Substance Abuse and Mental Health Services Administration (SAMHSA) has described residential treatment for substance use disorders as a direct service with multiple components that is delivered in a licensed facility used to evaluate, diagnose, and treat the symptoms or disabilities associated with an adult’s substance use disorder. SAMHSA has defined three levels of clinically managed residential services. All provide 24-hour care, but they offer treatment with varying intensity and focus depending on the resident’s needs. Table 1 presents a description of the components of this service.

Examination of the effectiveness of residential treatment for people with substance use disorders and for various subgroups is challenged by lack of a clear definition of service methods, treatment duration, and treatment standards. The objectives of this review were to describe models and components of residential treatment for substance use disorders, rate and discuss the level of evidence (that is, methodological quality) of existing studies, and describe the effectiveness of the service on the basis of the research literature. We focus on treatment for substance use disorders, although individuals in treatment may also have co-occurring mental disorders. Effectiveness studies primarily compared residential treatment for substance use disorders to other levels of care (for example, intensive outpatient treatment). Outcomes measured included drug and alcohol use, psychiatric symptoms, and other measures of psychosocial functioning.

Description of residential treatment

Residential treatment for substance use disorders is a setting in which services occur, rather than a discrete treatment intervention. A variety of therapeutic interventions may be implemented across different residential treatment settings; however, a common defining characteristic of residential treatment is that it provides housing for individuals who are in need of rehabilitation services.

Residential treatment occurs in nonhospital or freestanding residential facilities. Treatment for substance use disorders typically takes place in facilities that are licensed by each state’s Single State Agency for Substance Abuse Services. Residential treatment is part of the primary rehabilitation phase of treatment and may be preceded by detoxification, if warranted. Residential treatment should be followed by less intensive treatment and aftercare services within a continuum of care. A separate article in this series addresses intensive outpatient programs for substance use disorders (1).

Residential treatment for substance use disorders is used for a wide range of populations with a range of sociodemographic characteristics. For example, residential treatment is appropriate for individuals who have co-occurring mental and substance use disorders because of the challenges associated with having multiple disorders and their common need for intensive treatment in a safe environment. Residential treatment is also appropriate for individuals who are homeless, particularly because of the environmental challenges of achieving and maintaining sobriety or other aspects of recovery without stable housing.

The American Society of Addiction Medicine (ASAM) has spearheaded the complex task of developing specifications for addiction treatment at various levels of care and criteria to identify which individuals are most appropriate for which types of services (2,3). The ASAM patient placement criteria (ASAM PPC-2R) (2) consist of six dimensions: intoxication/withdrawal, medical conditions, mental health conditions, stage of change/motivation, recovery/relapse risks, and the recovery environment. Assessments on these dimensions are often used to place people into the level of care that matches their particular needs and provides a framework for treatment planning.

The ASAM PPC-2R (2) states that “the defining characteristic of all [residential] Level III programs is that they serve individuals who need safe and stable living environments in order to develop their recovery skills.” Individuals are considered appropriate for residential treatment, in particular, if they demonstrate a need for medical care, safe and stable housing, or a structured 24-hour recovery environment. Residential treatment services include a live-in setting that is housed in or affiliated with a permanent facility; organization and staffing by addiction and mental health personnel; a planned regimen of care with defined policies, procedures, and clinical protocols; and mutual- and self-help group meetings. The ASAM criteria informed the service-level definitions that are presented in Table 1. Residential treatment programs have specific programmatic and staffing requirements from the states in which they are licensed, which frequently (but not always or wholly) coincide with ASAM criteria.

ASAM describes most residential programs as clinically managed, meaning that they have a structured environment with skilled treatment staff but no on-site physician. Individuals are recommended for residential care if their withdrawal and biomedical needs are minimal, meaning that they did not experience acute withdrawal symptoms or they have already concluded the physical withdrawal process and no longer have a health risk related to withdrawal. Residents may have moderate psychiatric and general medical needs and significant challenges in the areas of treatment readiness, relapse potential, recovery skills, and environmental stability. The length of stay in nonhospital residential treatment has shortened considerably over time; most planned stays now range from weeks to months, depending on the program and the person’s needs.

Most studies of residential treatment use an acute care model in which outcomes are evaluated after treatment, rather than a chronic care model in which outcomes are evaluated during ongoing treatment—as is the case for a chronic condition such as hypertension or other medical comorbidity (4). Evaluations of treatment effectiveness for chronic disorders take place during the continuing care phase of treatment while patients are still receiving supportive care (albeit while living in the community), and permanent change is not expected in the absence of ongoing care. A continuum-of-care model for substance use treatment is critical whereby, after completion of residential treatment, participants are engaged continuously in less intensive forms of treatment to promote smooth transitions to self-management in the community (5,6).

Residential treatment models vary widely and have evolved over the years; this evolution presents challenges to efforts to compare research outcomes. The traditional “Minnesota model” was a planned 28-day residential treatment approach that is fairly rare today, as is the traditional hospital inpatient program with which residential treatment frequently has been compared.

A specific type of residential treatment setting is a therapeutic community. Therapeutic communities and other social model programs generally have a consistent approach, in which all aspects of the residential community are used as part of the treatment experience. The National Institute on Drug Abuse defines care within a therapeutic community as provided 24 hours per day in a nonhospital setting, with planned lengths of stay of six to 12 months. Treatment focuses on social and psychological causes and consequences of addiction. Treatment is structured and comprehensive, to “focus on the ‘re-socialization’ of the individual and use the program’s entire community—including other residents, staff, and the social context—as active components of treatment . . . [in] developing personal accountability and responsibility as well as socially productive lives” (7). A social model residential approach is similar to a therapeutic community.

Leaders in substance abuse and mental health policy arenas need information about the effectiveness of residential treatment for substance use disorders as they determine which interventions should be included as covered benefits in public and commercially funded health plans and as they make policy decisions about treatment interventions. This review aimed to provide state behavioral health directors and their staff, purchasers of health services, policy officials, and community health care administrators with an accessible summary of the evidence for residential treatment for substance use disorders and a discussion of areas needing further research.

Methods

Search strategy

To provide a summary of the evidence for and effectiveness of residential treatment for substance use disorders, we conducted a literature search of articles published from 1995 through 2012. We searched major databases: PubMed (U.S. National Library of Medicine and National Institutes of Health), PsycINFO (American Psychological Association), Applied Social Sciences Index and Abstracts, Sociological Abstracts, and Social Services Abstracts. We used combinations of the following search terms: residential treatment, substance use, substance abuse, dual diagnosis.

Inclusion and exclusion criteria

The following types of articles were included: randomized controlled trials (RCTs), quasi-experimental studies, and review articles such as meta-analyses and systematic reviews; U.S. and international studies in English; studies that focused on residential treatment for adults with substance use disorders or co-occurring mental health and substance use disorders; and studies that included outcomes such as measures of substance use.

Studies were excluded that examined residential treatment solely with adolescent populations and that examined residential treatment in criminal justice settings. Clients treated within the criminal justice system are likely to have other motivators for success (for example, to remain out of jail or prison), and thus the services and outcomes examined in these studies are not directly comparable to residential treatment services and outcomes examined elsewhere. Also excluded were studies that focused only on cost-effectiveness, did not have a comparison group, measured only length of stay or other effects that occurred during treatment, or used only pre-post analyses without statistical controls for baseline differences.

Existing review articles were given priority in this summary of the evidence. Individual articles are detailed here only if they were not previously included in a published review.

Strength of the evidence

The methodology used to rate the strength of the evidence is described in detail in the introduction to this series (8). The research designs of the identified studies were examined to determine that they met the inclusion criteria. Three levels of evidence (high, moderate, and low) were used to indicate the overall research quality of the collection of studies. Ratings were based on predefined benchmarks that took into account the number of studies and their methodological quality. In rare instances when the ratings were dissimilar, a consensus opinion was reached.

In general, high ratings indicate confidence in the reported outcomes and are based on three or more RCTs with adequate designs or two RCTs plus two quasi-experimental studies with adequate designs. Moderate ratings indicate that there is some adequate research to assess the service, although it is possible that future research could influence reported results. Moderate ratings are based on the following three options: two or more quasi-experimental studies with adequate design; one quasi-experimental study plus one RCT with adequate design; or at least two RCTs with some methodological weaknesses or at least three quasi-experimental studies with some methodological weaknesses. Low ratings indicate that research for this service is not adequate to draw evidence-based conclusions. Low ratings indicate that studies have nonexperimental designs, there are no RCTs, or there is no more than one adequately designed quasi-experimental study.

We accounted for other design factors that could increase or decrease the evidence rating, such as how the service, populations, and interventions were defined; use of statistical methods to account for baseline differences between experimental and comparison groups; identification of moderating or confounding variables with appropriate statistical controls; examination of attrition and follow-up; use of psychometrically sound measures; and indications of potential research bias. The evidence was rated as stronger when service and population definitions were clear and appropriate, statistical controls were used to account for baseline differences, and potential confounding variables and research bias (including attrition) were minimized.

Effectiveness of the service

We described the effectiveness of the service—that is, how well the outcomes of the studies met the goals of residential treatment. We compiled the findings for separate outcome measures and study populations, summarized the results, and noted differences across investigations. We evaluated the quality of the research design in our conclusions about the strength of the evidence and the effectiveness of the service. Although meta-analytic techniques would be valuable to assess the evidence across studies, the wide heterogeneity of the studies precluded this approach.

Results and discussion

Overall, we found a moderate level of evidence in the literature for the effectiveness of residential treatment for substance use disorders. Numerous RCTs and quasi-experimental studies were identified, but there were many methodological challenges within these studies. However, on the whole, the reviews and individual studies that were conducted found that residential treatment is an effective service for some types of patients. The level of evidence and the effectiveness of the service are described further below.

Level of evidence

The literature search identified eight research reviews published since 1995 that largely overlapped in the studies they included. The reviewed studies focused on adult participants with co-occurring mental and substance use disorders (9–11), inpatient populations (12,13), and therapeutic communities (14–16). We further evaluated seven individual RCTs that compared some version of residential treatment to a control condition (17–23) and 14 quasi-experimental studies (24–37). Table 2 and Table 3 summarize the features of the studies included in this review and their findings. The level of evidence for residential treatment for substance use disorders was graded as moderate, because this service met the criteria of having two or more RCTs with methodological weaknesses.

The studies lacked rigorous experimental design or quasi-experimental methods that controlled for patient characteristics. A focus on selected populations (for example, male veterans) and on a limited number of treatment sites limited the generalizability of several studies. Most effectiveness studies described here evaluated patients who chose or were referred by clinicians to a specific treatment modality. RCTs that evaluated specific treatment modalities for substance use disorders were rare because treatment providers had concerns about randomly assigning individuals in need of treatment to a no-treatment condition or to a lower level of care than was clinically appropriate. Some RCTs were conducted with a large limitation: the researchers required individuals in the intervention group to be appropriate for the outpatient care that was received by the comparison group, to avoid undertreating individuals who might not be treated safely if randomly assigned to outpatient care. This design created a false comparison, because individuals appropriate for residential treatment (and thus not appropriate for outpatient care) were excluded. Clients with more severe needs (for example, individuals without stable living arrangements or individuals with general medical or psychiatric diagnoses) were often excluded from the intervention group, despite the possibility that they were likely to benefit from residential services.

Many studies that suggested improved outcomes after residential treatment were excluded from this review because they lacked a comparison group or used pre-post measurement without statistical controls. Other methodological concerns in the literature included retrospective data collection, lack of control for the amount of treatment received, and lack of detailed descriptions of the service components. Comparison groups often varied by characteristics of the setting (for example, type of setting or treatment duration) and by treatment content (for example, services or theoretical approach), thereby confounding the comparisons. Each of these limitations influenced the conclusions that could be drawn.

Effectiveness of the service

The effects of residential treatment services were mixed, with some studies indicating positive findings and others showing no significant differences in outcomes between clients in residential treatment settings and those in other types of treatment. For example, the Walden House residential therapeutic community was compared with a therapeutic community model that used a day treatment program (18–20). At six months, both groups had reliable improvement in drug and alcohol use and employment. The Walden House group also had significant improvements in medical and social problems, psychiatric symptoms, and social support. Most outcomes seen at six months were maintained through 18 months (19); the day treatment group had a higher likelihood of relapse at six months but not at 12 or 18 months (18). In quasi-experimental studies, individuals receiving residential treatment had less methamphetamine use and crime (24), higher treatment completion rates and longer treatment stays (28), and reduced suicide attempts during treatment (29) compared with individuals receiving outpatient treatment. Individuals in inpatient residential treatment had lower alcohol and drug severity scores at six months than those in outpatient treatment, after control for baseline severity (30). De Leon and colleagues (25) found some evidence supporting treatment matching; clients matched to long-term residential care had better one-year outcomes than those undertreated in outpatient drug-free settings. Individuals with co-occurring mental and substance use disorders in integrated residential treatment settings had reduced illicit drug and alcohol use, improved psychiatric domains, higher reported quality of life, and improved social and community functioning than those in treatment as usual (9–11,15).

Reflecting the inconsistency in the literature, other studies showed no significant differences between individuals receiving residential treatment and those receiving treatment in comparison conditions on outcomes such as abstinence from drug use, psychosocial variables, reduced drug use, criminal activity, arrest rates, or rates of returning to prison (21–23,26,27,32,35–37). In an RCT, researchers compared treatment in a residential social model and in a nonresidential social model for homeless individuals with co-occurring mental and substance use disorders (17). No significant differences, aside from housing, were found between residential and nonresidential treatment groups at the three-month follow-up. When the analysis controlled for total services accessed, the residential group had significantly fewer days of alcohol use at the three-month follow-up, but no other significant effects were found.

The inconsistency in findings is documented by the literature reviews we examined. Published reviews of residential treatment reported on studies that had serious methodological limitations, resulting in the need for “an RCT with a well-defined population, a standardized program, and a blind assessment of outcomes” (9). Finney and colleagues (12,13) conducted two reviews that summarized the evidence on treatment settings—the first in 1996 and the second in 2009. The 1996 review included research on “inpatient” treatment compared with outpatient treatment or detoxification only (12). Although comprehensive at the time, the review was confounded for our purposes by the inclusion of both hospital inpatient approaches and nonhospital residential approaches and the exclusion of individuals with severe problems or without stable housing. In addition, many approaches described in the review article are no longer commonly used in the field; thus the article is not discussed further here. The 2009 review by Finney and colleagues (13) found evidence supporting the effectiveness of treatment that matched patients to different treatment settings, such as via the ASAM PPC-2R. However, the review provided little information about methods used in the included studies.

Three reviews examined the effects of therapeutic communities on substance use outcomes (14–16). A Cochrane Collaboration review indicated that insufficient evidence exists to state that therapeutic communities are more effective than other levels of care; however, methodological limitations tempered the researchers’ conclusions (15). High attrition was a common limitation in the reviewed studies. Some evidence suggested that specific populations, such as homeless individuals with co-occurring mental disorders or individuals in prisons, had better outcomes in therapeutic communities than control groups. The second review found that individuals in therapeutic communities demonstrated improved outcomes compared with individuals in control conditions; however, the findings were limited by various methodological issues, such as overlap between the treatment and comparison conditions and inconsistent program fidelity (16). The third review found significant decreases in substance use while individuals were in therapeutic communities but indicated that methodological problems tempered the extent to which conclusions could be drawn about the long-term effects of therapeutic communities (14). Similar to other reviews, the third review found that therapeutic communities may provide a better treatment option for individuals with severe psychosocial problems, depending on the length of stay in the program.

Three reviews (9–11) focused on populations with co-occurring mental and substance use disorders. The experimental group usually received integrated residential treatment (for individuals with co-occurring disorders), and control groups received “treatment as usual” with less intense or nonintegrated residential treatment. These reviews found that individuals with co-occurring mental and substance use disorders can be treated successfully in residential settings, whether or not treatment is integrated. At minimum, integrated treatment was equally as effective as standard treatment for this population, and most of the studies found that integrated treatment was more effective than standard treatment in regard to substance use, mental health, and other outcomes.

Conclusions

This review found a moderate level of evidence for the effectiveness of residential treatment (see box on this page). Despite the prevalence of methodological concerns—primarily the appropriateness of the samples and equivalence of comparison groups—some evidence indicates that residential treatment is effective for some types of patients. Further, much of the literature suggests that residential treatment is equally as effective as comparison modalities, and a few studies suggest that it is more effective. However, until research with more rigorous methods is conducted, these conclusions remain tentative.

We echo the call of others for further research to better determine which clients benefit from residential treatment, what duration of treatment confers positive effects, and what types of effective clinical interventions are provided within the program. Further studies should examine the components of residential treatment that might relate to effectiveness, such as types of clinical staff, use of peer support, number of beds, or lengths of stay currently used. To attain ideal outcomes, it is essential for new evaluations of residential treatment for substance use disorders to take a chronic care approach to ensure that a treatment modality is not evaluated in a vacuum and that continuing care is an outcome as well as an essential part of the treatment episode.

Any new research in this area must be methodologically rigorous and use appropriate comparison groups to ensure that conclusions are valid. Systematic, rigorously conducted studies are essential for policy makers to make decisions about the inclusion of residential treatment in health plans and the allocation of resources to residential treatment activities.

Specifically, research needs to identify which individuals respond best to residential treatment programs. Studies should use appropriate control groups. Future research needs to reflect current approaches to residential treatment and examine the role of treatment factors (such as staffing and length of stay) in contemporary approaches to residential treatment. Research must include posttreatment variables, such as mutual-help participation, when evaluating outcomes. Examining effective treatments for individuals with substance use disorders requires furthering our understanding of how to improve treatment retention, length of stay, treatment completion, and participation in aftercare.

Finally, it is important to determine whether treatment services are equally effective for different populations. Given the significance of health disparities in access to and receipt of substance use treatment, implementing effective and culturally responsive care is essential. Most studies described the demographic characteristics of the sample, and some studies controlled for these characteristics in analyses. However, no studies specifically analyzed race or ethnicity through interaction terms, stratification, or other approaches. Examining the effectiveness of treatment across different groups requires analyses comparing outcomes of specific subgroups within and across treatment types. Additional work should analyze the role of culture-specific approaches—for example, multilingual staff. We encourage researchers to incorporate such analyses as we continue to evaluate this treatment modality.

In addition to calling for rigorous research on the current system, we note that the moderate level of evidence for the effectiveness of residential treatment of substance use disorders has relevance for consumers and their families as well as for policy makers. Consumers have a wide range of needs, and they would benefit from a variety of services to address those needs. Residential treatment for substance use disorders fills a niche for consumers who require stable living environments that incorporate therapeutic treatments to help them move toward a life in recovery. Similarly, to reduce the likelihood of treatment failure, policy makers should ensure that a full range of treatments is available to meet consumer needs. With research demonstrating a moderate level of evidence, policy makers can highlight the benefit of including residential treatment as a key service in the continuum of care.

As the treatment system for substance use disorders continues to evolve, particularly within the current context of broader health care system change, it is essential to understand the role and effectiveness of treatment options. Residential treatment has been used for substance use disorders for many years, and there are clear indications for continuing these services. However, for policy makers and payers (for example, state mental health and substance use directors, managed care companies, and county behavioral health administrators) to be able to make recommendations about which services to cover and include in a treatment continuum, they must be able to evaluate those services as they currently exist. Residential treatment shows value for ongoing inclusion and coverage as part of the continuum of care, but additional rigorous research is necessary to understand how and for whom it best fits.