The primary results of this analysis of patient-rated alliance in MET for substance use problems were that (1) contrary to our hypothesis, there was no significant difference between MET and CAU therapists in mean alliance scores, (2) therapists did vary significantly in their mean alliances, both for MET and CAU, (3) variability in the alliance at the patient level (within therapist) was not significantly related to outcome during Weeks 4 to 16, but variability at the therapist level evidenced a curvilinear (quadratic) relation to drug/alcohol use outcomes during Weeks 4 to 16, (4) there was no significant difference in the relation between alliance and outcome in MET compared to CAU, and (5) across therapists, fundamental and advanced MET techniques were significantly associated with the between-therapist alliance scores.
The fact that MET did not produce higher alliances than CAU was surprising. The extensive focus in MET on empathy, acceptance, and positive regard, as well as clear discussion about goals, would be expected to produce higher alliances in MET compared to CAU. The lack of a treatment difference was especially surprising given that MET adherence ratings were significantly related to the alliance, and MET adherence scores were substantially higher in MET compared to CAU sessions (Martino et al., 2008
). Thus, one conclusion is that forming a positive alliance is not unique to MET; very positive average alliance can occur in CAU among therapists never trained in MET.
There are several potential explanations, however, why a treatment difference related to ratings of alliance did not occur. For one, the alliance has been shown to be related to patient pretreatment characteristics, such as expectations for improvement and certain types of interpersonal problems (Gibbons et al., 2003
; Muran et al., 1994
). To the extent that these patient characteristics are relatively stable over time, the aspect of the alliance that is related to these patient characteristics would not be expected to change depending on type of therapy, particularly when alliance is measured after the second treatment session, as it was here. Studies that have shown that the alliance can change as a function of treatment typically measure alliance multiple times later in treatment (Crits-Christoph et al., 2006
; Hilsenroth et al., 2002
Second, CAU therapists (like the MET therapists) were mostly highly experienced, averaging 8.5 years working with these kinds of patients. Experienced therapists might be expected to typically form relatively high alliances, leaving little room for MET to improve upon CAU. Consistent with this possibility, the average alliance score (dividing the total score by the number of items) was 5.1 on a 1 to 6 scale for both MET and CAU. If MET (adequately implemented) and CAU were compared using inexperienced therapists, the alliance-enhancing potential of training in MET might be more likely to be evident.
A third reason may be that the CAU therapists in the current study frequently used open questions and reflections, and were rated close to an average level of MI style in their sessions (Martino et al., 2008
). While MET and CAU were discriminable, there may have been enough of the client-centered counseling skills happening in CAU to result in good alliances. Increasing empathy and reflections above a basic level may have little incremental impact on the alliance.
Our study adds to existing findings that report therapist effects on the alliance. Like Baldwin et al. (2007)
, we found that the therapist variability in the alliance, but not the patient variability, was associated with outcome (reduced drug/alcohol use). This is an important distinction because it suggests that something that therapists are doing in sessions (e.g., differences in interpersonal style, abilities to learn and implement alliance-fostering techniques, or identify and repair alliance ruptures) determines, at least in part, the alliance. As reported in Ball et al. (2007)
, there were no overall significant therapist effects on outcome in the current study, suggesting that the between-therapist alliance-outcome relation found here is not part of a more general therapist effect for which the alliance is simply a marker. Furthermore, the effect size for the alliance-outcome relationship found in the present study is comparable to that in the literature. The Cohen's d
effect size of 0.39 found here converts to an r
of 0.191 for the linear between-therapist effect of the alliance on outcome; the d
= 0.44 for the quadratic effect converts to an r
of 0.215. These effects are similar to the average r
of 0.22 reported by Martin et al. (2000)
in their meta-analysis of studies examining the relation of the alliance to outcome, despite the fact that, unlike the studies in the meta-analysis, our effect size is specific to the between-therapist relation and controls for improvement up to the assessment of the alliance.
To the extent that the between-therapist component of the alliance is related to treatment outcome, but not the within-therapist component, conceptualizations of the alliance as primarily an interactional variable (e.g., Henry & Strupp, 1994
) may need to be modified. If the alliance is primarily a function of interpersonal processes unique to each dyad, then one would expect meaningful variation between patients who are treated by the same therapist, and that this variation between patients should be related to treatment outcome. The fact that the between-therapist variability, but not the between-patient variability, was found to relate to outcome suggests that relative differences between therapists in skill level, or personal qualities, are leading to a tendency for patients within a therapist's caseload to be reacting in a similar and meaningful way to a given therapist. While patient variables also impact the alliance (Gibbons et al., 2003
; Muran et al., 1994
), the variability between therapists in their ability to form a relatively more positive or negative alliance appears to be a more important determinant of outcome, as least as evidenced from the two studies (the current study and Baldwin et al., 2007
) that have examined both patient and therapist variability in the alliance in relation to outcome.
Assuming the alliance plays a direct or indirect causal role in psychotherapy or drug counseling, the current findings suggest that efforts to train therapists in ways that might enhance the alliance are justified. Recent training studies have provided preliminary evidence that such training can be accomplished (Crits-Christoph et al., 2006
; Hilsenroth et al., 2005
). However, it is also possible that innate personality characteristics of therapists determine the alliance, at least in part, and these characteristics may not be teachable. In addition, treatments that do not have a special, explicit, MET-like focus on empathy and positive affirmations, such as cognitive-behavioral therapy (e.g., Bouchard et al., 2004
) or the CAU in the current study, often display very high average alliance scores; therefore, training in the use of MET-like techniques does not appear to be the only vehicle for achieving a positive alliance. Thus, it seems likely that only a subset of therapists, those of any orientation who have a relatively impaired ability to form positive alliances, might benefit from training in how to enhance the alliance.
Furthermore, the relation between the alliance and outcome with alcohol and substance abusing populations may be complicated by the fact that many patients can readily become abstinent from drugs and alcohol early in treatment. Sustaining such abstinence, or reducing the severity and frequency of relapses, is more difficult, and it is in this treatment phase when alliance may most impact treatment outcomes. Many studies, however, measure outcome in a way that confounds reductions in drug use and prevention of slips and relapses. In the current study, assessing outcome in two phases, the first of which largely captured the initial reduction in drug use to near zero (Weeks 1 to 4) and the second that potentially captured slips and relapses (Weeks 4 to 16), revealed that the alliance was primarily related outcomes during the follow-up period.
In the current study, a more positive alliance was not necessarily a good thing: A curvilinear (quadratic) relation between the alliance (between-therapist component) and rate of change in primary drug/alcohol use during Weeks 4 and 16 was found. This indicates that deviations from the average alliance in both directions (relatively low and relatively higher than the average) were associated with relatively poorer outcomes. This type of finding was reported early in the history of alliance research by Saunders, Howard, and Orlinsky (1989)
, but has largely been overlooked since then, with investigators assuming a linear relation of the alliance to outcome. Further research is needed to understand the basis of this quadratic effect of alliance and outcome, and whether such an effect is evident across different types of therapies, patients, and settings.
High levels of therapist use of both MET fundamental techniques and MET advanced techniques were associated with high levels of alliance. Caution is warranted in interpreting the adherence data given the relatively high correlation between the fundamental and advanced adherence subscales, incomplete data (not all sessions were rated), and the standard limitations of correlational findings (i.e., reverse causation, influence of third variables). Within the constraints of these limitations, we can speculate that both fundamental techniques (e.g., positive affirmations, use of open-ended questions, use of reflective statements) and advanced techniques (e.g., problem discussion and feedback, exploring pros/cons/ambivalence, heightening discrepancies, discussing a plan for change) contribute to the fostering of the alliance. It may be that fundamental techniques are useful for strengthening the bond component of the alliance while advanced techniques help move the dyad towards greater agreement on goals and tasks. The findings with the adherence scale also suggest that the negative impact of high alliance on outcome is not a function of high levels of use of MET fundamental or advanced techniques. When these variables were included in the statistical model predicting substance use from the alliance, the curvilinear relation did not change, suggesting that some other factors are likely to be producing the finding of very high alliances being associated with relatively poorer drug use outcomes. Therapists implementing MET should therefore not be concerned that high use of these techniques has a detrimental effect on outcome by fostering an overly positive alliance. The MET adherence scale, however, was not designed to measure all alliance-fostering techniques. Thus, other alliance-fostering techniques not measured in the MET adherence scale may be responsible for the curvilinear relation that we found.
Several other limitations are important to consider in understanding this study's results. First, alliance was measured only after Session 2. This was done because the treatment was only three sessions long and it was important to assess the alliance early in treatment before most clinical improvement had occurred. Some previous studies of the alliance, however, have measured it later in treatment, giving more time for a bond to develop or for alliance ruptures and repairs to occur. It is possible that different results would be obtained if alliance was assessed after Session 3 or if treatment had been longer. Second, restricting CAU to three sessions limits the generalizabilty of the results to clinical settings where CAU is typically longer. Third, the fact that patients across conditions also participated in group counseling sessions, potentially led by MET or CAU counselors, is a limitation that may have attenuated our findings. Fourth, a substantial portion of patients randomized did not have alliance scores or did not have outcome measures. The lack of data on some randomized patients may have introduced bias in the comparison of treatments. Fifth, the time spent in training was not balanced across treatment conditions. Therapists assigned to MET received regular supervision based on tape reviews throughout the trial. This supervision difference between the treatments may have impacted the results in unknown ways. Sixth, although therapists were randomly assigned to treatment conditions, random assignment of patients to therapists was not performed. If systematic biases existed at clinics in regard to which therapists received which patients, such biases could create the therapist differences in the alliance that were found, and also be responsible for the between-therapist effect for the alliance in relation to outcome (assuming patient factors are related to the alliance and outcome). Seventh, both the predictor variable (alliance) and outcome measure (drug use) were self-report measures. The study's findings should be confirmed using an observer measure of the alliance. Finally, during this period of time in which alliance predicted drug use (Weeks 4 to 16), patients may have been receiving additional non-study treatment services at the original clinic or another clinic, with patients who were increasing their drug use being more likely to receive such services. Increased additional services during follow-up is associated with drug use outcomes (Worley et al., 2008
), and this might have attenuated the relation of the alliance to outcome during Weeks 4 to 16.
Research on the relation of the alliance has evolved significantly in recent years. Early studies almost always examined only simple correlations between the alliance and outcome. More recently, there has been attention to the unpacking of the multiple levels of analysis, particularly patient and therapist (Baldwin et al., 2007
) as well as site, in multicenter trials. Other issues including the effects of early improvement in symptoms on the alliance–outcome correlation (Barber et al., 2000
; Crits-Christoph, Gibbons, & Hearon, 2006
), the possibility of curvilinear effects (Saunders et al., 1989
), and the role of patient factors that might cause good alliances (Gibbons et al., 2003
), all have added to an awareness of the complexity of research on the alliance in relation to outcome.