Our findings give some support the hypothesis that the interpersonal accuracy of learning statement interventions is important to treatment outcome especially as measured by social adjustment. However, our results suggest that the direction of the relation between interpersonal accuracy of learning statement interventions and treatment outcome differs by type of treatment. Specifically, higher accuracy scores were related to poorer outcomes in CT but relatively better outcomes in IPT. These differential effects were found in the prediction of various outcomes, including depressive symptoms and social adjustment over the course of active treatment.
The accuracy scores for the three CCRT components (wish, response from other, response of self) were relatively uncorrelated. This indicates that when therapists in the current study were accurate on one aspect of a relationship pattern they were not necessarily accurate on other facets of the pattern. Perhaps this result is not unexpected given that the therapists in the TDCRP were not trained in the CCRT method and therefore did not likely think about relationship themes in the same coherent way as contained within the CCRT method. However, because prediction of outcome was achieved for accuracy scores on both the wish and response of self elements, our findings suggest that addressing each of these aspects of a relationship theme may be useful. In addition to low correlations among the accuracy scores, there was no evidence of therapist effects on the accuracy scores. These findings suggest that it is not the case that some therapists are consistently “accurate” and others not “accurate.” In the TDCRP sample, interpersonal accuracy of learning statements varied from dyad to dyad.
This study addresses a major methodological weakness of previous studies of interpersonal accuracy of therapists’ interventions by including data from multiple assessment points across treatment. Previous studies of interpersonal accuracy (Crits-Christoph et al., 1988
; Norville et al., 1996
; Piper et al., 1993
) only assessed outcome pre- and posttreatment. The existence of the 4-week HRSD and SAS assessments in the TDCRP permitted early improvement (from baseline to Week 4) to be statistically controlled; the assessments at Weeks 4, 8, 12, and 16 permitted a better estimate of the trajectory of change over treatment. By controlling for early improvement on the HRSD and SAS, the current findings suggest that the relation between interpersonally accurate learning statement interventions and treatment outcome is not a spurious correlation produced by early improvements leading to both more accurate interventions and better treatment outcomes.
The finding of a differential relationship between interpersonal accuracy and treatment outcome in IPT and CT suggests that these treatments may, in part, achieve comparable results through different mechanisms. Within the context of a psychotherapy that focuses on interpersonal relationships, it is perhaps not surprising that more accurate learning statement interventions lead to better treatment outcomes. Such accurate interventions are likely to be seen as more empathic and have the potential to increase patient insight into the nature of their interpersonal difficulties. What is surprising is that accurate learning statement interventions led to relatively poorer outcomes in CT.
One factor to consider in understanding the relation between interpersonal accuracy and outcome in CT is that a previous report documented that CT tends to have fewer relationship episodes than IPT as well as more therapist words spoken while patients are describing a relationship episode (Crits-Christoph et al., 1999
). Because of the greater amount of interpersonal material in sessions, it might be expected that IPT therapists would be able to have a better understanding of patients’ interpersonal themes and therefore achieve relatively higher levels of accuracy in their interventions. However, on most of the accuracy measures, no mean differences between CT and IPT were apparent. On one measure (accuracy on the response of self), CT was found to have higher mean levels of accuracy compared to IPT. In addition, the standard deviations for the accuracy measures were similar or higher in CT compared to IPT. Thus, the differential prediction of outcome across IPT and CT for some of the accuracy measures does not appear to be due to relatively lower levels, or lower variability, of accuracy scores in CT preventing a similar relation emerging with outcome as was found in IPT.
Our finding of differential prediction in CT versus IPT is discrepant from previous process studies conducted using sessions from the TDCRP. Krupnick et al. (1996)
reported that the therapeutic alliance predicted outcome across all four treatment conditions in the TDCRP, with virtually no differences between treatments in the nature of the relationship between alliance and outcome. Ablon and Jones (1999)
found that patient process qualities (e.g., “patient feels helped,” “patient achieves a new understanding”) were significantly related to treatment outcome across IPT and CT. Based on their findings, these authors have emphasized that the common elements in these psychotherapies are the factors responsible for the general finding of no difference between the psychotherapies in treatment outcome. Although common factors may well have contributed to the result of no differences between the psychotherapies in treatment outcomes, the current findings suggest that processes unique to each treatment may also be contributing. Interpersonal accuracy, as defined here, may be facilitating positive outcomes in IPT but hindering positive outcomes in CT. In CT, the quality of implementation of CT techniques may be leading to better outcomes (Shaw et al., 1992).
The negative relationship between interpersonal accuracy of interventions and treatment outcomes in CT may appear discrepant from other studies that have pointed to the positive impact of an interpersonal or psychodynamic focus in CT. In particular, Hayes, Castonguay, and Goldfried (1996)
found that interventions that addressed the interpersonal and developmental domains were associated with greater improvement in CT, and Jones and Pulos (1993)
found that greater use of psychodynamic techniques in CT was associated with relatively more favorable outcomes. The different findings of these studies compared to the current one may be a function of the type of process measures used. Neither the Hayes, Castonguay, and Goldfried (1996)
nor the Jones and Pulos (1993)
study assessed the interpersonal content of relationship themes for each patient so that therapist accuracy in addressing these themes could be examined. It may be that doing the work of CT within interpersonal domains is helpful in CT but that focusing extensively on the content of interpersonal wish and response components, rather than on automatic thoughts and beliefs, is distracting from the primary task of CT. In addition, alternative measures of interpersonal focus in CT may be more appropriate to studying interpersonal aspects of therapist techniques. Methodological differences between the studies, such as our use of early improvement as a covariate and predicting the slope of change from Week 4 to Week 16, may also be responsible for the divergent findings.
Our predictive findings occurred with the ratings of accuracy in regard to recurrent themes that were apparent across multiple relationship episodes. Thus, it appears to be particularly important within IPT to address recurrent relationship themes rather than only addressing situational specific relationship problems. Our findings therefore suggest that the IPT model could likely be enhanced by having therapists focus more on formulating and addressing the unique recurrent interpersonal themes of each patient. IPT therapists are trained to address interpersonal issues within the context of the four main domains of interpersonal problems (role transitions, interpersonal deficits, interpersonal disputes, and/or interpersonal loss/grief) described in the IPT manual, but no specific system for formulating individual patient recurrent themes is provided for IPT therapists (although case examples are given in the manual). Therefore, to enhance IPT, the integration of formulation systems for interpersonal themes such as the CCRT method might be considered.
A number of limitations of the findings presented here should be noted. First, the specific direction of the interactions between accuracy of interpersonal interventions and treatment type were not hypothesized in advance and therefore these findings should be replicated. This is especially important because only some of the accuracy measures predicted outcome and no correction for multiple analyses was applied. Thus, the current findings need to be considered preliminary. Second, although we attempted to avoid a spurious finding that can result from predicting change from baseline to termination from process measures that are sampled after baseline, we have not ruled out the influence of other "third variables" on our correlational findings. Third, it is likely that aspects of therapist statements other than their interpersonal accuracy are relevant to treatment outcome. This appears to be especially true in CT, where interpersonal accuracy may have a negative impact. Not only are other aspects of therapist interventions important, but a complete picture of the change process would incorporate various patient, therapist, and process variables to account for treatment outcome differences across patients. Fourth, as mentioned, the measure of interpersonal accuracy of interventions may not capture the way in which interpersonal issues are addressed within the context of CT. Fifth, some of the QUAINT items retained for analysis had marginal reliabilities and many items not retained for analysis had weak reliabilities. More reliable methods of assessing an expanded set of interpersonal wishes and responses may yield stronger, or different, findings than presented here. Despite these limitations, the current study provides some clues about how the process of IPT and CT may be different and how aspects of these treatments beyond “common factors” may in part be responsible for therapeutic change.