Aims-Motivational interviewing (MI) is an efficacious treatment for substance use disorders. However, little is known about how MI exerts its therapeutic effects. This review is a first attempt to summarize and evaluate the evidence for purported within-session mechanisms of change. The primary question of interest was: Which MI constructs and variables appear to be the most promising candidates for mechanisms of change?Methods-Literature searches were conducted to identify studies delivering MI in an individual format for the treatment of substance use disorders. Our search identified a total of 152 studies for review; 19 studies met inclusion criteria by providing data on at least one link in the causal chain model under examination. Effect size estimates were calculated for every possible step in the causal model where sufficient data were provided by study authors.Results-Four constructs of therapist behavior were evaluated: MI Spirit, MI-Consistent behaviors, MI-Inconsistent behaviors, and therapist use of specific techniques. Five constructs of client behavior were evaluated: change talk/intention, readiness to change, involvement/ engagement, resistance, and the client's experience of discrepancy. The absence of experimental and full mediation studies of mechanisms of change was notable. Effect sizes were generally mixed.Conclusions-The most consistent evidence was found for three constructs: client change talk/ intention (related to better outcomes); client experience of discrepancy (related to better outcomes); and therapist MI-Inconsistent behavior (related to worse outcomes). Regarding therapist use of specific techniques, use of a decisional balance exercise showed the strongest association to better outcomes.

Objective The technical hypothesis of motivational interviewing (MI) posits that therapist implemented MI skills will be related to client speech regarding behavior change and that client speech will predict client outcome. The current meta-analysis is the first aggregate test of this proposed causal model. Method A systematic literature review, using stringent inclusion criteria, identified k = 16 reports describing 12 primary studies. Review methods calculated the inverse-variance-weighted pooled correlation coefficient for the therapist to client and the client to outcome paths across multiple targeted behaviors (i.e., alcohol or illicit drug use, other addictive behaviors). Results Therapist MI-consistent skills were correlated with more client language in favor of behavior change (i.e., change talk; r = .26, p < .0001), but not less client language against behavior change (i.e., sustain talk; r = .10, p = .09). MI-inconsistent skills were associated with less change talk (r = −.17, p = .001) as well as more sustain talk (r = .07, p = .009). Among these studies, client change talk was not associated with follow-up outcome (r = .06, p = .41), but sustain talk was associated with worse outcome (r = −.24, p = .001). In addition, studies that examined composite client language (e.g., an average of negative and positive statements) showed an overall positive relationship with client behavior change (r = .12, p = .006; k = 6). Conclusions This meta-analysis provides an initial test and partial support for a key causal model of MI efficacy. Recommendations for MI practitioners, clinical supervisors, and process researchers are provided.

Objective In the present meta-analysis, we test the technical and relational hypotheses of Motivational Interviewing (MI) efficacy. We also propose an a priori conditional process model where heterogeneity of technical path effect sizes should be explained by interpersonal/relational (i.e., empathy, MI Spirit) and intrapersonal (i.e., client treatment seeking status) moderators. Method A systematic review identified k = 58 reports, describing 36 primary studies and 40 effect sizes (N = 3025 participants). Statistical methods calculated the inverse variance-weighted pooled correlation coefficient for the therapist to client and the client to outcome paths across multiple target behaviors (i.e., alcohol use, other drug use, other behavior change). Results Therapist MI-consistent skills were correlated with more client change talk (r = .55, p < .001) as well as more sustain talk (r = .40, p < .001). MI-inconsistent skills were correlated with more sustain talk (r = .16, p < .001), but not change talk. When these indicators were combined into proportions, as recommended in the Motivational Interviewing Skill Code, the overall technical hypothesis was supported. Specifically, proportion MI consistency was related to higher proportion change talk (r = .11, p = .004) and higher proportion change talk was related to reductions in risk behavior at follow up (r = −.16, p < .001). When tested as two independent effects, client change talk was not significant, but sustain talk was positively associated with worse outcome (r = .19, p < .001). Finally, the relational hypothesis was not supported, but heterogeneity in technical hypothesis path effect sizes was partially explained by inter- and intra-personal moderators. Conclusions This meta-analysis provides additional support for the technical hypothesis of MI efficacy; future research on the relational hypothesis should occur in the field rather than in the context of clinical trials.

Objective-Evaluate moderators and mediators of brief alcohol interventions conducted in the Emergency Department. (18-24 years; N = 172) in an Emergency Department received a motivational interview with personalized feedback (MI) or feedback only (FO), with 1-and 3-month booster sessions and 6-and 12-month follow ups. Gender, alcohol status/severity group (ALC+ Only, AUDIT+ Only, ALC+/AUDIT+), attribution of alcohol in the medical event, aversiveness of the event, perceived seriousness of the event, and baseline readiness to change alcohol use were evaluated as moderators of intervention efficacy. Readiness to change also was evaluated as a mediator of intervention efficacy, as were perceived risks/benefits of alcohol use, self-efficacy, and alcohol treatment seeking. Methods-PatientsResults-Alcohol status, attribution, and readiness moderated intervention effects such that patients who had not been drinking prior to their medical event, those who had low or medium attribution for alcohol in the event, and those who had low or medium readiness to change showed lower alcohol use 12 months after receiving MI compared to FO. In the AUDIT+ Only group those who received MI showed lower rates of alcohol-related injury at follow up than those who received FO. Patients who had been drinking prior to their precipitating event did not show different outcomes in the two interventions, regardless of AUDIT status. Gender did not moderate intervention efficacy and no significant mediation was found.Conclusions-Findings may help practitioners target patients for whom brief interventions will be most effective. More research is needed to understand how brief interventions transmit their effects. Keywords Alcohol; Brief Intervention; Emergency RoomAlcohol is one of the primary causes of injuries treated in trauma centers (1), and Emergency Department (ED) patients are up to three times more likely to report heavy drinking and negative consequences of drinking than patients in primary care settings (2).Corresponding Author: Nancy P. Barnett, Center for Alcohol and Addiction Studies, Brown University, Box G-S121-5, Providence, RI 02912, USA, Nancy_Barnett@brown. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptMales and younger patients are more likely to have been drinking prior to treatment in an ED (3), and patients who are admitted to a trauma center with positive toxicology findings have twice the subsequent injury mortality rates than other patients (4).Use of early, brief interventions may prevent the development of more severe cases of alcohol problems (5), and may reduce the risk of future health problems or injury (6-8). The importance of treating alcohol problems among ED and trauma center patients is reflected in national recommendations (9), and a recent mandate that requires all trauma centers to provide screening and brief intervention services for alcohol problems (10). Motivational Interviewing (MI) (11) reduces drinking and/or associated problems with patients in EDs or trauma ce...

and the investigation of relational factors. In meta-analyses some variation will always exist, whether due to chance or to differences in trial context or content [5,6]. On its own, variance in a meta-analysis does not de-legitimize that meta-analysis, nor does it necessarily mask key causes of variation. Indeed, once these relational factors are specified , measured and tested in the same way in which specific factors are currently dealt with, meta-analyses of the trials of these new tests would still be subject to variation in outcome due to remaining unspecified factors. Miller & Moyers are right to point out that, in focusing exclusively on specific factors related to treatment content, research into addiction treatments may be overlooking important relational factors and their associated effects. However , in acknowledging genuine and measurable causes of variation-more trees, arguably-it is important that a true forest view is not obscured. Using existing methodology , findings can be aggregated without masking the impact of underlying mechanisms, as long as these potential mechanisms are identified in advance. Relational factors that can be measured empirically and in which therapists can be trained can be tested in randomized controlled trials, as has recently been done with empathy in the context of physician training [7,8]. Such trials could then be aggregated in meta-analyses. Even where not tested directly , the contribution of these relational factors could be examined in systematic reviews through meta-regression, as has already been performed with specific factors [9,10].

Objective To identify individual therapist behaviors which elicit client change talk or sustain talk in motivational interviewing sessions. Method Motivational interviewing sessions from a single-session alcohol intervention delivered to college students were audio-taped, transcribed, and coded using The Motivational Interviewing Skill Code (MISC), a therapy process coding system. Participants included 92 college students and eight therapists who provided their treatment. The MISC was used to code 17 therapist behaviors related to the use of motivational interviewing, and client language reflecting movement toward behavior change (change talk), away from behavior change (sustain talk), or unrelated to the target behavior (follow/neutral). Results Client change talk was significantly more likely to immediately follow individual therapist behaviors [affirm (p = .013), open question (p < .001), simple reflection (p < .001), and complex reflection (p < .001)], but significantly less likely to immediately follow others (giving information (p < .001) and closed question (p < .001)]. Sustain talk was significantly more likely to follow therapist use of open questions (p < .001), simple reflections (p < .001), and complex reflections (p < .001), and significantly less likely to occur following therapist use of therapist affirm (p = .012), giving information (p < .001), and closed questions (p < .001). Conclusions Certain individual therapist behaviors within motivational interviewing can either elicit both client change talk and sustain talk or suppress both types of client language. Affirm was the only therapist behavior that both increased change talk and also reduced sustain talk.

Objective Each year, thousands of college students receive mandated intervention as a sanction for alcohol use or alcohol-related behavior. For these mandated students, Brief Motivational Interventions (BMIs) are currently the most efficacious individual intervention. However, little is known about how the technical (therapist behaviors) and relational (e.g., global ratings of therapist empathy) components of BMIs influence client language as well as subsequent change in alcohol use and consequences in mandated students. Method This study used the Motivational Interviewing Skills Code (MISC 2.0; Miller, Moyers, Ernst, & Amrhein, 2003) to code BMI sessions from two randomized clinical trials that facilitated significant reductions in alcohol use (Study 1, n = 91) and alcohol-related consequences (Study 2, n = 158) in mandated students. Results There were significant relationships among therapist behaviors, global scores, and client language both for and against change, yet there were no links between in-session client language and subsequent changes in alcohol use or problems. In contrast, relational aspects of MI (global ratings of therapist MI Spirit and client self-exploration) were most predictive of post-session alcohol use. Mediation models incorporating both technical and relational components revealed that higher levels of client self-exploration mediated the relationship between higher therapist ratings of MI Spirit and improved drinking at follow-up. Conclusions Findings highlight the importance of considering how both technical and relational components of MI may influence alcohol use in mandated college students, and also suggest more exact analyses to better understand this complex relationship.

ABSTRACT. Objective: The aim of this research was to study marijuana use, associated risks, and response to brief motivational intervention among young adult drinkers treated in an emergency department. Method: Study participants (N = 215; ages 18-24) were in a randomized controlled trial for alcohol use that compared motivational interviewing with personalized feedback (MI) with personalized feedback only. Pastmonth marijuana users were compared with nonusers on demographics, readiness, self-effi cacy, and behavioral risk variables. Marijuana use was examined as a potential moderator of alcohol outcomes. Whether marijuana use alone or combined marijuana and alcohol use would be reduced as a result of brief intervention for alcohol was examined at 6 and 12 months. Results: Current marijuana users were younger, were more likely to be white, and reported more alcohol use, other illicit drug use, and more alcohol-related consequences than nonmarijuana users. Marijuana use at baseline did not moderate response to brief alcohol treatment. Marijuana use declined from baseline to 6 months for both treatment groups, but only MI participants continued to reduce their use of marijuana from 6-to 12-month follow-up. Reductions in number of days of use of marijuana with alcohol appeared to be primarily a function of decreased alcohol use. Conclusions: Young adult drinkers reporting current marijuana use are at generally higher risk but responded to brief alcohol treatment by reducing alcohol and marijuana use. , 1988) and in adult ED patients treated for alcohol problems (Woolard et al., 2003); and greater injury-related risk has been shown among patients using both alcohol and marijuana (Soderstrom et al., 1988;Woolard et al., 2003).Medical settings provide an opportunity for screening (Chung et al., 2003) and early intervention with non-treatment-seeking alcohol and marijuana users (Degutis, 2003). ED studies of brief motivational interventions (BMIs) for alcohol have demonstrated positive outcomes with older adolescent and young adult samples (Monti et al., 1999(Monti et al., , 2007. Although studies have effectively targeted multiple risk behaviors for injury among adolescents in the ED (Johnston et al., 2002), we found no published studies that targeted multiple substances with older adolescents or young adults in ED settings. However, BMI has reduced both alcohol and marijuana use among adult ED patients more than standard services (Woolard et al., 2008). A few studies have targeted multiple substances with college students, and a recent study examined adolescent substance use in a general medical setting. D'Amico and colleagues (2008) found greater reduction of marijuana use in a BMI compared with usual services among at-risk adolescents recruited in a primary care clinic. BMI and written personalized feedback were effective in reducing alcohol, nicotine, and marijuana use with mandated college students (White et al., 2006(White et al., , 2007, and non-help-seeking college students decreased alcohol, nicotine, and ...