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Co-Directors: Varda Shoham & Michael Rohrbaugh
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Mediators and Moderators of BSFT for Adolescent Drug Use |
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National Institute on Drug Abuse (NIDA)
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Grants # R01 DA17539 and U10 DA15815
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Principal Investigator: |
Varda Shoham, Ph.D. Department of Psychology University of Arizona |
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Co-Principal Investigators: |
Michael J. Rohrbaugh, Ph.D. Department of Psychology University of Arizona |
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Jose Szapocznik, Ph.D. Center for Family Studies University of Miami |
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Michael Robbins, Ph.D. Center for Family Studies University of Miami |
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Daniel Feaster, Ph.D. Center for Family Studies Florida International University |
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Please do not quote or cite without permission |
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SPECIFIC AIMES
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Brief Strategic Family Therapy (BSFT) is an empirically-supported treatment for adolescent drug abuse that places heavy emphasis on engaging adolescents' families in the therapy process. Previous research on this and other promising drug abuse treatments has focused largely on outcome comparisons, giving little attention to how a treatment works (mediator questions) or for whom it may be especially beneficial (moderator questions). The purpose of the study proposed here is to test theory-derived hypotheses about mediators and moderators (M&Ms) of BSFT's effect on adolescent substance abuse, as well as on secondary outcomes such as reduced externalizing and risky sexual behavior. Because BSFT attempts to change problem-maintaining aspects of the adolescent's natural support system, particularly patterns of family interaction, we hypothesize that family functioning plays a critical mediating and moderating role in effective implementation of this treatment. Knowledge of specific family-linked mediators should facilitate exporting BSFT to community settings via therapist training focused on effective ingredients of change. Similarly, knowledge of specific moderators should increase the potential applicability of BSFT by identifying youth and families likely to benefit from this treatment relative to other treatments. These emphases fit well with NIDA's program of Stage II and Stage III treatment development research. The thrust of our study is to use the Clinical Trials Network (CTN) as a platform for testing M&M hypotheses about BSFT. In the parent grant (CTN-0014), a large two-arm randomized clinical trial (RCT) beginning later this year, BSFT will be compared to treatment as usual (TAU) for adolescent substance abuse in 14 community treatment programs (CTPs) around the country. Therapists selected from the staffs of these CTPs will be randomly assigned to conduct one of the two treatments, with therapists in the BSFT condition trained and supervised by staff from the University of Miami's Center for Family Studies, where the approach originated. The parent grant will fund standardized self-report assessments at baseline (T0) and at 4 months (T4), 8 months (T8), and 12 months (T12) following the initiation of treatment, as well as monthly assessments of drug use. The current grant will fund additional, more intensive data collection based on direct observation of family and therapeutic interactions vital to testing M&M hypotheses. This includes (a) ratings of videotaped family interaction at baseline and 4 months for both treatment groups, coded according to the Structural Family Systems Ratings scheme (SFSR); and (b) ratings of therapist adherence and competence (treatment fidelity) in the first and fourth sessions for BSFT cases only. Finally, because a large (N=84) pool of therapists will also be randomized to treatments, the design provides a rare opportunity to study training processes related to effective treatment implementation. To this end we will collect supplementary data on all therapists prior to their randomization (e.g., professional experience, recovery status, theoretical orientation) and on skill-acquisition trajectories of the BSFT therapists as they progress through training and the clinical trial. In addition to its virtues for external validity, this CTN protocol design affords unique opportunities to study M&Ms both between treatments (capitalizing on randomization to BSFT and TAU) and within the BSFT treatment itself. We will test M&M hypotheses and explore related (secondary) research questions within the context of the following specific aims: Aim 1: To investigate family functioning as a mediator of the differential effectiveness of BSFT v. TAU. Based on a central assumption of family-systems theory, we expect that family-level structural change will lead to (i.e., precede) improvement in the presenting problem. By this logic, symptom change following any treatment for adolescent drug abuse should work to the extent that it alters problem-maintaining family relationships – and BSFT should be more likely to accomplish this kind of system change than the typical TAU. The family dimensions we consider most important in this respect are structure (e.g., unbalanced family alliances, collapsed or reversed hierarchy), resonance (e.g., enmeshment or disengagement), developmental stage (e.g., age and role appropriateness), identified patienthood (e.g., scapegoating), and conflict resolution. Hypothesis 1 (H1): Changes in family functioning at T4 (relative to T0) will mediate the predictive association between treatment condition (BSFT v. TAU) and decreasing trajectories of drug use from T4 to T12. This will be demonstrated statistically if controlling intermediate family change reduces (partial mediation) or eliminates (full mediation) associations between treatment condition and outcome. In addition to testing H1, we will explore whether the mediating role of family change is greater when initial (T0) family functioning is relatively poor. One might expect such moderated mediation because family change in higher-functioning families may be more constrained by a ceiling effect. (On the other hand, several BSFT studies suggest that family functioning may actually decrease in the course of certain individually-focused TAUs, in which case absolute amounts of family change may be less constrained than one might expect.) Aim 2: To investigate within BSFT the mediating role of family change in explaining associations between observed intervention quality (therapist adherence/competence) and clinical outcomes. At the core of BSFT's theory of change is a two-stage intervention sequence in which the therapist first joins with the family, then works to "restructure" family interaction patterns relevant to the maintenance of drug abuse. This implies an idealized process in which (a) joining in sessions 1 and 2 sets the stage for (b) restructuring from session 3 onward, which leads to (c) family change observable at T4, and ultimately to (d) reduced drug use from T4 to T12. Hypothesis 2: Within BSFT, associations between the quality of early joining/restructuring interventions and clinical outcomes at T5 through T12 will be mediated by changes in family functioning from T1 to T4. As with Aim 1, a secondary analysis will examine the possibility that the mediating role of family change will be greater when initial (T0) family functioning is poor. Exploratory process analyses will also determine whether the quality of therapist joining in session 1 predicts the family's subsequent therapy attendance, and whether the time course of joining, restructuring, reframing, and tracking interventions across the first 4 sessions accords with the idealized BSFT model (e.g., increased restructuring efforts from session 1 to session 4). Aim 3: To investigate family functioning as a moderator of the differential effectiveness of BSFT v. TAU. Relative to TAU, we expect BSFT to be most advantageous when family functioning is poor, particularly on the structural dimensions cited in aim1 above. In other words, relative to TAU, BSFT should level the playing field with respect to risk factors related to family pathology. Hypothesis 3: Outcome and engagement differences between BSFT and TAU will be greater when family pathology at T0 is high compared to when it is low. Secondary analyses will examine the relative, unique contributions to moderation of family functioning (a relational variable) and individual measures of the individual adolescent's problem severity (e.g., substance use, co-occurring externalizing behavior). If the correlation between family and individual pathology is low enough to permit a direct comparison of individual and relational moderators, we expect the family-level moderator may be more potent. Other potential moderators to be considered in secondary analyses include ethnicity (e.g., Hispanic v. Anglo-American), adolescent gender, household composition. and the presence of a co-occurring psychiatric disorder. Aim 4: To investigate family functioning as a moderator of associations between intervention quality (therapist adherence) and subsequent clinical outcomes within BSFT. Consistent with H3, the kind of family-level interventions BSFT provides should be most critical when initial family functioning is poor, so we expect quality joining and restructuring to be most predictive of outcome when family pathology is severe. Hypothesis 4: Observer ratings of BSFT intervention quality will show stronger predictive associations with clinical outcome when family pathology is high rather than low. Here, too, we will explore whether the moderating role of family functioning equals or exceeds that of possible individual-level moderators such as drug use severity or the extent of anti-social youth behavior. Aim 5: To compare the contributions and relative potency of observational v. self-report measures of family functioning in the M&M analyses outlined above. The theory and practice of BSFT privileges direct observation of family interaction over assessment based on self-report. This advantage of observational methods has been found in several areas of family research, including our own. For this reason we expect the SFSR ratings to pay dividends as M&Ms, thereby justifying the additional cost of observational data collection. (If self-report measures of family functioning mediate and/or moderate just as well, however, this will be important to know.) Aim 6: To explore and refine procedures for selecting and training BSFT therapists. Random assignment of community therapists to treatments in this CTN protocol provides a unique opportunity to examine therapist characteristics that may predict clinician suitability for BSFT v. TAU based on differential client outcomes. In addition, given that at least 28 BSFT therapists are expected to participate in the full CTN trial and 42 will receive training, we aim to identify therapist and training-process variables relevant to effective real-world implementation of this treatment. For example, near the end of their 3-month BSFT training experience, prospective therapists will undergo evaluation by a panel of three BSFT experts who review case notes and randomly selected videotapes of therapy sessions. The panel completes a BSFT Therapist Certification Checklist, and on the basis of this decides if the therapist will be certified for participation in the clinical trial. Whereas the goal of training and certification is to guarantee a minimally acceptable level of BSFT proficiency, and this may truncate the range of therapist skills observed within the trial, it is very important to understand the relationship between therapist characteristics, skills, and proficiency on the one hand and participant outcomes on the other. We will therefore examine (a) whether pre-training therapist characteristics (e.g., education, experience, recovery status, beliefs about drug abuse and treatment) predict therapist case outcomes in different ways for BSFT and TAU; (b) whether, within BSFT, these characteristics predict the level and trajectory of skill acquisition during training; (c) whether BSFT skill trajectories during training predict therapist case outcomes; and (d) whether significant trajectories of skill acquisition also occur after the training phase (i.e. during the intervention phase) and relate to prior training trajectories or concurrent case outcomes. Analyses for this aim are purely exploratory due to limited ns for sub-aims b, c, and d (which apply to BSFT only) and the absence of firm a priori hypotheses. In sum, our overarching goals in pursuing these 6 specific aims are (a) to test hypotheses about how and for whom BSFT works, and (b) to sharpen strategies for effective implementation and dissemination to community settings.
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