1. PREDICTIVE VALIDITY OF THE MMPI-2: CLINICAL SCALE DISTURBANCE
AS AN INDICATOR OF COGNITIVE BEHAVIORAL THERAPY TREATMENT OUTCOME
Christopher B. Harte1, Martita Lopez1, & Raymond C. Hawkins II2,1
1University of Texas at Austin 2Fielding Graduate University
I N T R O D U C T I O N
Table 1: Demographics of the Participant Sample
Table 2:
Effects of Treatment for the Entire Group and for Specific Diagnostic
Subgroups Irrespective of MMPI-2 Characteristics
Figure 1:
Number of MMPI-2 Clinical Scale Elevations
and Symptom Reduction (w/in group Δ)
C O N C L U S I O N
Many studies report that comorbid Axis 1 diagnoses1,2 and high pre-treatment symptom distress predict poorer treatment outcomes.
The present study explored the predictive validity of the MMPI-2 clinical scales for CBT outcomes for clients treated primarily for anxiety or depressive disorders.
Specifically, we examined whether the amount of MMPI-2 psychiatric disturbance (breadth), irrespective of the level of distress (intensity), predicted treatment response.
Although patients with high MMPI-2 disturbance have more disorder-specific axis I distress at pre- and end-treatment, their attenuation of distress is parallel to patients with low to moderate disturbance.
However, when treatment outcome is determined using reliable change indices and clinical significance cutoffs, patients with high MMPI-2 clinical scale disturbance are approximately three times as likely as those with low disturbance to be nonrecovered. This was not a function of the level of distress at pre-treatment.
Additionally, because the number of Axis I diagnoses was controlled, the statistically significant findings suggests that the MMPI-2 may uniquely contribute to predicting CBT outcomes.
The present study has several strengths including:
Treatment of patients with a variety of disorders and tailored disorder-specific measures.
Use of z-scores to pool across diagnostic categories while maintaining the integrity of the original disorder-specific measure.
Rigorous categorical classification using clinical significance and reliable change.
Error bars represent SEMs.
Maximum possible clinical scale elevations = 8 (scale 5 and 0 removed)
A I M
Table 3:
Number of MMPI-2 elevations and Treatment
Response Classification
Table 4:
Figure 2:
Number of MMPI-2 Clinical Scale Elevations and
Symptom Reduction (between-group comparisons)
To determine whether the MMPI-2 clinical scales may uniquely contribute to predicting CBT outcomes
Number of MMPI-2 elevations and Treatment
Response Classification (Adj ORs)
M E T H O D S
PARTICIPANTS
189 patients assessed with both the SCID-I and SCID-II who received at least 8 CBT treatment sessions (see Table 1).
Patients treated for anxiety disorders (n = 159) or depressive disorders (n = 30).
Data taken from a university training clinic practice research database consisting of 456 patients treated by trained graduate student clinicians.
ABREVIATIONS: AOR: Adjusted Odds Ratio; BDI-II: Beck Depression Index, Version II; CBT: Cognitive behavioral therapy; CS: Clinical Significance; DSM-IV: Diagnostic and Statistical Manual for of mental Disorders; ES: effect size; LSAS: Leibowitz Social Anxiety Scale; MMPI-2: Minnesota Multiphasic Personality Inventory – Version 2; OR: Odds Ratio; PAI: Panic Appraisal Inventory; PSWQ; Penn State Worry Questionnaire; RC: Reliable Change; SCID: Structured Interview Diagnostic for the DSM-IV; SEM: Standard error of the mean; Y-BOCS; Yale-Brown Obsessive Compulsive Scale
Error bars represent SEMs.
Maximum possible clinical scale elevations = 8 (scale 5 and 0 removed)
ANALYSIS
Overall Treatment Response
For each disorder-specific measure, patients were categorized into 6 treatment outcome groups.
Nonresponders were classified as being nonrecovered and exhibiting maintenance/ deterioration with respect to their CS and RC scores,
Responders were categorized into 2 tiers of stringency per each measure: (i) stringent responders: patients who improved and recovered: and (ii) lenient responders: patients who improved but did not recover.
Patients who recovered and demonstrated either maintenance or deterioration were removed from analyses.
R E F E R E N C E S
MEASURES
R E S U L T S
In terms of treatment outcome classification, patients with high MMPI-2 disturbance (6-8 elevated clinical scales) were sig less likely to be recovered compared to mild disturbance (0 -2 elevations). This pattern held when both the strictly (OR = 0.38, P = .03) and leniently (OR = 0.43, P = .05) classified (see Table 3).
Because number of Axis 1 diagnoses covaried with number of MMPI-s elevations, the former variable was entered as a covariate in subsequent logistic regression analyses. Results were still significant and indicated that compared to patients with low disturbance, patients with high disturbance were more likely to be classified as nonresponders. Again this held when both the strictly (AOR = 0.34, P = .04) and leniently (AOR = 0.42, P = .07) classified (see Table 4).
Overall, age, education, ethnicity, gender, as well as overall distress (F scale) and test-taking approach (L scale) did not moderate treatment outcome.
MMPI-2
MMPI-2 administered at pre-treatment. The number of elevated (T ≥ 65) clinical scales was used as a marker psychiatric disturbance.
Disorder-Specific Assessments
Validated measures specific to a patient’s diagnosis assessed at pre- and end-treatment (see Table 2).
Indices of Treatment Response
Reliable Change: [(x2 – x1)/Sdiff], where x1 is pretest score and x2 is posttest score; Sdiff = √[2(SE)2], and SE = s1√(1-rxx), where s1 is the standard deviation of the control group, and rxx is the test-retest reliability of the measure5. This categorized patients into 3 groups: improvement, maintenance, deterioration.
Clinical Significance: for all measures, the cutoff for clinical significance was taken as the midpoint between the mean of controls and the mean of psychiatrically affected5. This categorized patients into 2 groups: recovered, nonrecovered.
Reich JH, Green AL (1991). The Journal of Nervous and Mental Disease, 179,
Reich JH, Vasile RC (1993). The Journal of Nervous and Mental Disease, 181,
Jacobson NS, Truax P (1991). Journal of Consulting and Clinical Psychology, 59,
Not all of the 189 participants received end-treatment disorder specific measures and therefore only 132 participants were included in analyses.
Irrespective of MMPI-2 characteristics, 5/7 groups showed a sig reduction of symptoms (see Table 2).
Patients with high (6-8 elevated scales) disturbance demonstrated sig higher pre- and end-treatment z scores compared to patients with either low (0-2 elevated scales) or moderate (3-5 elevated scales) disturbance (see Figure 2).
However, from pre- to end-treatment, all groups demonstrated significant reduction in symptoms, and decreases were parallel indicating that the amount of disturbance did not differentially affect the magnitude of symptom reduction (see Figure 1).
ACKNOWLEDGEMENTS
We thank Michael Telch, Ph.D., David Collins, Ph.D., and all graduate student clinicians who supervised, screened, assessed, and treated these patients. We also thank all patients who took part in this study.
Magnitude of Symptom Change
Pre- and end-treatment scores for each disorder-specific measure were z-transformed within-subjects, yielding mean pre- and post-treatment z scores for each axis I diagnosis, as well as overall pre- and end-treatment z scores pooled across Axis I diagnoses.
Orlando, Florida 2008