1. Can the MMPI-2 predict outcomes from cognitive-behavioral treatments
for anxiety disorders?
Ray Hawkins, Martha Spriggs, Hanjoo Lee, & Martita Lopez
Fielding Graduate University The University of Texas at Austin
Introduction
Abstract. The integration of objective personality measures into cognitive behavioral interventions is controversial (Shadel, 2004), but potentially important for implementing practice research networks for treatment effectiveness studies. In this paper we report preliminary data gathered from a training clinic archival database to explore the predictive validity of the MMPI-2 for CBT outcomes for clients treated for anxiety disorders. The anxiety disorder diagnoses consisted of panic disorder with or without agoraphobia (PD, n=45), generalized anxiety disorder (GAD, n=35), and social phobia (SP, n=74). DSM-IV diagnoses were verified using the Structured Clinical Interview (SCID), idiographic cognitive-behavioral case formulations were made, and treatment (a median of 11 sessions) was provided according to published CBT treatment manuals. The MMPI-2, general self-report measures (e.g., Beck Depression Inventory, Beck Anxiety Inventory), and domain-specific measures of core maintaining factors (e.g., Panic Appraisal Inventory, Anxiety Sensitivity Index, Penn State Worry Questionnaire) were administered as part of a baseline psychological evaluation. These self-report scales were also given every 2-3 weeks until the end of treatment to measure outcomes. The preliminary results show that several of the correlations of the MMPI-2 clinical scales with the post-treatment domain-specific outcome measures, or with pre- to post-treatment change scores, attained statistical significance, but these effects were attenuated, or disappeared entirely, when the contributions of baseline BDI and/or BAI scores were partialled out. We also examined whether MMPI-2 scales could discriminate those clients who showed clinically significant improvements in end-state functioning (Jacobson & Truax, 1991) from those who did not. Separate analyses conducted within the PD, GAD, and SP diagnostic groups did not reveal any difference in MMPI-2 clinical scale mean scores between the "improved" vs. "not improved" clients. We tentatively conclude that the MMPI-2 clinical scales may add very little value to the goal of predicting in CBT outcomes in treatment effectiveness studies. At the University of Texas Clinical Psychology Training Clinic we have found the MMPI-2 to be more useful for an idiographic case conceptualization and "therapeutic assessment" that may strengthen the therapist-client relationship (i.e., Finn, 1996), but this application, and its causal mechanism(s), should be also be empirically validated.
Results
The preliminary results show that several of the correlations of the MMPI-2 clinical scales with the post-treatment domain-specific outcome measures, or with pre- to post-treatment change scores, attained statistical significance, but these effects were attenuated, or disappeared entirely, when the contributions of baseline BDI and/or BAI scores were partialled out. We also examined whether MMPI-2 scales could discriminate those clients who showed clinically significant improvements in end-state functioning (based on Jacobson's 1984 criteria) from those who did not. Separate analyses conducted within the PD, GAD, and SP diagnostic groups did not reveal any difference in MMPI-2 clinical scale mean scores between the clients that showed clinically significant improvement (“CSI”) and those who were not improved (“No CSI”) according to the criteria of Jacobs & Truax (1991).
Discussion
Pearson correlations of outcome measures with MMPI-2 Clinical Scales
Partial correlations of MMPI-2 Scales with outcome measures,
controlling for baseline values
The MMPI-2 is a ubiquitous measure of personality that has shown limited value in predicting
outcomes in psychotherapy in general and in CBT in particular. These preliminary results, although
supporting the Michael et al. (2004) finding that an MMPI-2 composite measure (derived from 8
clinical scales) did significantly predict some outcome measures (e.g., BDI end, BDI change), the
amount of variance explained was modest (approximately 5%), only about 25% that accounted for
by the baseline scores on the CBT domain specific scales (e.g., BDI, BAI). Moreover, MMPI-2
clinical scale elevations were generally unrelated to global outcome (i.e., CSI vs. No CSI). Only two
of the 32 t-tests conducted attained statistical significance.
There are several limitations of this study that should be mentioned. Although this clinical data base
contained clients with clinically significant levels of anxiety disorder (as verified by SCID DSM-IV
diagnoses and elevated scores on domain specific measures), who were treated by doctoral
students being trained in the use of manualized ESTs, with outcomes that were comparable
to published benchmark treatment effectiveness studies (e.g., Hawkins et al., 2004), nevertheless
it was based on a relatively small convenience sample lacking a comparison or control group.
Does the MMPI-2 have utility in CBT? We have found the MMPI-2 to be more useful for an idiographic
case conceptualization and treatment planning. Cluster analysis of MMPI-2 clinical and content scales
may be useful to identify subgroups that overlay DSM-IV Axis I anxiety disorder categories. We are
currently investigating this possibility.
MMPI-2 Clinical Scales
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Outcome Measures
Treatment Outcome
Figure 3. MMPI-2 Clinical scales, PD/ PD AG Group (N=45),showing clients with “clinically significant improvement”
(CSI, n=25) vs. clients without clinically significant Improvement (No CSI, n=16). T-tests revealed no statistically significant differences for the MMPI-2 clinical scales between the CSI and No-CSI subgroups, except a trend for “Sc” (CSI < No CSI, p = .052)
* p < .05; ** p < .01
Table 1. The Pearson bi-variate correlations for the MMPI-2
clinical scales with each of the outcome measures showed
several statistically significant relationships (62 out of 180).
Table 2. Partial correlation analyses revealed that 13
statistically significant relationships remained after the
contribution of the baseline scores was removed.
Literature Review
Conclusions
Evaluation of psychological assessment tools as predictors of therapeutic outcome could contribute to the existing body of knowledge regarding clinical effectiveness, but few conclusions about specific instruments have been reached to date. A review of the literature revealed little information regarding the MMPI-2 (Butcher, 1997) in predicting therapeutic outcome. Chisholm, Crowther and Ben-Porath (1997) examined selected MMPI-2 scales’ ability to predict premature termination and psychotherapeutic outcome. Findings revealed that elevations in content scales (DEP and ANX) were stronger predictors of therapeutic progress than were elevations on scales 2 and 7, and elevations on scale 4 predicted improvement in global psychopathology scores. The outcome measures used by Chisholm, et al. were based on individual therapist’s ratings, rather than on objective measures. Clearly, a gap in the literature exists regarding the predictive value of the MMPI-2 scales in therapeutic outcome, particularly with regard to specific types of psychotherapy and standardized measures of treatment outcome. Michael, Furr, Masters, Collett, Spielmans (2004, July) have recently examined the utility of the MMPI-2 clinical scales to predict clinically significant change in psychotherapy. A multiple regression analysis using 8 MMPI-2 scales (excluding Mf and Si) was run against scores from the Outcome Questionnaire-45 (OQ-45) for a sample of 48 patients from a community clinical sample who were referred to a university-based clinic for outpatient therapy. The multiple regression model did not yield statistically significant results due to the relatively small sample size, along with a high degree of multicollinearity among the scales which occurred in that particular sample. Consequently, a composite scale score was computed and used in the model, and results indicated a negative correlation between elevated levels of psychopathology and symptom reduction as measured by the OQ-45. Results of a logistic regression analysis also revealed that elevations on the Pt, Sc, Pd and Hy scales predicted the poorest chance of clinically significant improvement as measured by the OQ-45. We decided to conceptually replicate the Michael et al. findings using archival clinical data gathered over the past 14 years from the University of Texas Clinical Psychology Training Clinic.
We tentatively conclude that the MMPI-2 clinical scales may add very little value to the goal of predicting CBT outcomes in treatment effectiveness studies. At the University of Texas Clinical Psychology Training Clinic we have found the MMPI-2 to be more useful for an idiographic case conceptualization and "therapeutic assessment" that may strengthen the therapist-client relationship (i.e., Finn, 1996), but this application, and its causal mechanism(s), should be also be empirically validated.
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References
Treatment Outcome
Treatment Outcome
Figure 1. MMPI-2 Clinical scales, Entire Anxiety Group (N=140),
showing clients with “clinically significant improvement”
(CSI, n=74) vs. clients without clinically significant
Improvement (No CSI, n=66). T-tests revealed no
statistically significant differences for any of the MMPI-2
clinical scales, or for the composite score, between the CSI
and No-CSI subgroups.
Figure 4. MMPI-2 Clinical scales, GAD Group (N=35), showing clients with “clinically significant
improvement” (CSI, n=18) vs. clients without
clinically significant Improvement (No CSI, n=15). T-tests revealed no statistically significant
differences for any of the MMPI-2 clinical scales
between the CSI and No-CSI subgroups.
Butcher, J.N. (1997). Personality assessment in managed health care: Using the MMPI-2 in treatment
planning. NY: Oxford University Press.
Chisholm, S. M., Crowther, J. H., & Ben-Porath, Y. S. (1997). Selected MMPI-2 scales' ability
to predict premature termination and outcome from psychotherapy. Journal of Personality Assessment,
69(1),
Finn, S.E. (1996). Manual for using the MMPI-2 as a therapeutic intervention. Minneapolis: University of
Minnesota Press.
Hawkins, R.C. II, & Lopez, M.A. (2004, July). Treatment effectiveness in the training clinic: A preliminary
outcomes study. Paper presented at the American Psychological Association convention, Honolulu, HI.
Michael, K.D., Furr, R.M., Masters, K.S., Collett, B.R., Spielmans, G.I. (2004, July) .Predicting clinically
significant in psychotherapy: The utility of the MMPI-2. Poster presented at the American Psychological
Association convention, Honolulu, HI.
Jacobson, N.S., & Truax, P. (1991). Clinical significance: A statistical approach to defining meaningful
change in psychotherapy research. Journal of Consulting and Clinical Psychology, 29 (1),
Shadel, W.G.(2004). Introduction to the special series: What can personality science offer cognitive-
behavioral therapy and research? Behavior Therapy, 35(1),
Method
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For Further Information
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The MMPI-2, general self-report measures (e.g., Beck Depression Inventory,
Beck Anxiety Inventory), and domain-specific measures of core maintaining
factors (e.g., Panic Appraisal Inventory, Anxiety Sensitivity Index, Penn State
Worry Questionnaire) were administered as part of a baseline psychological
evaluation. These self-report scales were also given every 2-3 weeks until the
end of treatment to measure outcomes. “Clinically significant improvement”
(CSI) was defined for each outcome measure according to the method of
Jacobson & Truax (1991). For each client treated a global CSI outcome was
determined by an algorithm (i.e., global CSI indicated when at least one outcome
measure was CSI and no other outcome measure showed a significant
deterioration in outcome).
Ray Hawkins, Ph.D., ABPP (Clinical Psychology)
Core Faculty, Fielding Graduate University,
Associate Faculty, Episcopal Theological Seminary of the Southwest
Lecturer, Psychology Department
The University of Texas at Austin
1 University Station A8000
Austin, TX
Phone:
Anxiety Subgroup
Treatment Outcome
Figure 2. MMPI-2 8 Clinical scales, Comparing subgroups. PD / PD AG
(n= 45), GAD (n=35), and SP (n=74). Note that the groups overlap
somewhat due to co-morbidity for these anxiety disorders, and
accordingly no statistical comparisons were carried out.
Figure 5. MMPI-2 Clinical scales, SP Group (N=74),
showing clients with “clinically significant
improvement” (CSI, n=35) vs. clients without
clinically significant improvement (No CSI, n=37).
T-tests revealed no statistically significant
differences for the MMPI-2 clinical scales
between the CSI and No-CSI subgroups, except for
“Hy” (CSI < No CSI, p = .04)