Response to Cognitive Therapy in Depression the Role of Maladaptive Beliefs and Personality Disorders

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Response to Cognitive Therapy in Depression The Role of Maladaptive Beliefs and Personality Disorders

Willem Kuyken School of Psychology University of Exeter Nicole Kurzer Department of Psychology University of Pennsylvania Robert J. DeRubeis Department of Psychology University of Pennsylvania Aaron T. Beck Department of Psychiatry University of Pennsylvania Gregory K. Brown Department of Psychiatry University of Pennsylvania ABSTRACT

This study examined whether personality disorder status and beliefs that characterize personality disorders affect response to cognitive therapy. In a naturalistic study, 162 depressed outpatients with and without a personality disorder were followed over the course of cognitive therapy. As would be hypothesized by cognitive theory ( A. T. Beck & A. Freeman, 1990 ), it was not personality disorder status but rather maladaptive avoidant and paranoid beliefs that predicted variance in outcome. However, pre- to posttherapy comparisons suggested that although patients with or without comorbidity respond comparably to "real-world" cognitive therapy, they report more severe depressive symptomatology at intake and more residual symptoms at termination.

There have been numerous randomized clinical trials that support the efficacy and effectiveness of cognitive therapy for depression ( A. T. Beck, Rush, Shaw, & Emery, 1979 ) across a variety of clinical settings (for a review, see Clark, Beck, & Alford, 1999 ; DeRubeis & Crits-Christoph, 1998 ). However, rates of dropout, treatment nonresponse, and relapse are considerable (e.g., Elkin et al., 1989 ; Evans et al., 1992 ) and demand better understanding of the factors associated with treatment response ( Scott, 1996 ).

One factor that may account for some depressed patients' having a limited response to cognitive therapy is the presence of a comorbid personality disorder ( Pretzer & Beck, 1996 ). Several studies involving other treatment modalities have indicated that when depression is comorbid with a personality disorder it is associated with a poorer response to psychotherapy ( Perry, Banon, & Ianni, 1999 ), pharmacotherapy ( Sato, Sakado, Sato, & Morikawa, 1994 ), and combined treatment ( Pilkonis & Frank, 1988 ). Other studies, however, have not supported this association (e.g., Black, Bell, Hulbert, & Nasrallah, 1988 ).

In an effort to improve the treatment response for depressed patients with comorbid personality disorders, cognitive therapy has been adapted for these populations (e.g., A. T. Beck & Freeman, 1990 ; Young, 1994 ). Cognitive theory of personality disorders proposes that personality disorders comprise a relatively stable organization of cognitive, affective, behavioral, motivational, and physiological

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schemas for representing responses to external and internal demands ( Pretzer & Beck, 1996 ). These schemas are rigid, typically include avoidant strategies, and fail to process disconfirming inputs into the cognitive system. Pretzer and Beck have suggested that individuals with personality disorders have developed maladaptive cognitive processes and maladaptive behavioral strategies that render them more vulnerable to recurrent depression. Furthermore, each personality disorder is characterized by specific clusters of maladaptive beliefs. For example, individuals with an avoidant personality disorder might believe strong feelings are intolerable and thus should be avoided ( A. T. Beck & Freeman, 1990 ). For these patients, this belief affects how they process information, subsequently feel, and behave. Consistent with this theory, several researchers have reported that individuals with personality disorders have dysfunctional cognitions that are rigid and persistent even after a depressive episode remits ( Ilardi & Craighead, 1999 ; Zuroff, Blatt, Sanislow, Bondi, & Pilkonis, 1999 ).

It follows that in cognitive therapy, patients with comorbidity may find it difficult to change their maladaptive beliefs. Therefore, researchers hypothesized that the rates of comorbidity would be higher among nonresponders and partial responders than among responders. Initial findings addressing this hypothesis have yielded conflicting results.

The National Institute of Mental Health Treatment of Depression Collaborative Research Program involved 239 outpatients with major depressive disorder, 74% of whom also had a personality disorder ( Elkin et al., 1989 ). The presence of a personality disorder predicted a worse outcome in terms of social functioning and self-report depressive symptoms at the end of treatment, but not in terms of work functioning or clinician-rated depressive symptoms ( Shea et al., 1990 ). In contrast, in a further randomized controlled trial and a naturalistic outpatient study, the presence of a personality disorder was not a significant factor in cognitive therapy outcome ( Hardy et al., 1995 ; Persons, Burns, & Perloff, 1988 ).

Given these inconsistent findings, the present study examined whether personality disorders, and the specific maladaptive beliefs that characterize particular personality disorders ( A. T. Beck, Butler, Brown, & Dahlsgaard, 2000 ), are associated with a poorer treatment response to cognitive therapy. Specifically, we hypothesized that greater levels of maladaptive beliefs would be associated with the worse treatment outcome. We included both established categorical systems for diagnosing personality disorders and more recently developed theory-driven measures of maladaptive beliefs in personality disorders ( A. T. Beck & Beck, 1991 ).

Method

Sample

The study participants were 162 outpatients who received cognitive therapy at the Center for Cognitive Therapy (CCT), University of Pennsylvania. The sample comprised 93 (57%) women and 69 (43%) men. The mean age of the sample was 33.61 ( SD = 11.91), ranging from 18—73 years old. Fifty-one (32%) participants were married, 4 (2.5%) were widowed, 16 (10%) were divorced or separated, and 91 (56%) were single (never married). Three (2%) patients indicated a range of 7th—11th grade as the highest level of education obtained, 17 (11%) had a high school diploma or its equivalent, 44 (27%) completed some college, 47 (29%) had a college degree, and 48 (30%) had attended graduate or professional school. Three patients did not indicate their educational background.

Primary and secondary Axis I diagnoses and psychiatric symptomatology at intake are shown in Table 1 . With respect to Axis II diagnoses, 96 (59%) patients were diagnosed with a personality disorder, 23 (14%) were deferred, and 26 (16%) were diagnosed as having no Axis II disorder. Of those patients

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diagnosed with an Axis II disorder, the breakdown into specific diagnoses was: 3 (3%) paranoid, 19 (20%) borderline, 1 (1%) histrionic, 3 (3%) narcissistic, 13 (14%) obsessive—compulsive, 21 (22%) avoidant, 6 (6%) dependent, and 30 (31%) personality disorder not otherwise specified (NOS). 1

Procedure

After patients signed voluntary consent forms, doctoral-level diagnosticians conducted intake evaluations comprising the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (4th ed.) DSM-IV Axis I and Axis II disorders (SCID—I; First, Spitzer, Gibbon, & Williams, 1995a , 1995b ; SCID—II, First, Spitzer, Gibbon, Williams, & Benjamin, 1994 ) and a battery of psychological assessments. Reliability of SCID diagnoses was ensured as follows ( Zimmerman, 1994 ). All diagnosticians were postdoctoral clinicians who received training on the SCID—II before conducting diagnostic evaluations. Axis II diagnoses were obtained through the use of the SCID—II screening questionnaire and SCID—II interview. In the latter part of the intake evaluation, there was a three-way meeting among a senior clinical psychologist, the diagnostician, and the patient to confirm diagnosticians' impressions. Inclusion criteria were a primary diagnosis of major depressive disorder, dysthymia, or depressive disorder NOS. Exclusion criteria were bipolar disorder, psychosis, and dementia.

After the intake evaluation, patients began cognitive therapy with 1 of 33 doctoral-level therapists. Therapists treated an average of 4.29 patients ( SD = 4.24, range 1—17). All participating therapists received the CCT 2-week didactic training in cognitive therapy before beginning their clinical work and subsequently received supervision from experienced cognitive therapists. Therapists had an average of 2.52 ( SD = 2.66, range 1—10) postdoctoral years experience.

A measure of therapist competence was developed and is fully reported elsewhere ( Kuyken, 2000 ). The CCT clinical director and a senior staff psychologist rated therapists' cognitive therapy competence on a 7-point scale. Both raters reviewed therapy tapes and directly supervised the therapists. Interrater reliability was substantial (κ = .80) and showed good convergent validity, with mean general competence ratings that were routinely given by therapists' supervisors during their tenure at the CCT ( r s = .59, p < .001, N = 74). Mean competence scores were 4.53 ( SD = 1.08, range 2—6), suggesting that the majority of therapists were regarded as very competent.

All patients received cognitive therapy. This was delivered according to therapist clinical judgment, individualized patient formulations, and treatment plans that were collaboratively agreed on between therapist and patient ( J. S. Beck, 1995 ). Generally, treatment comprised standard cognitive therapy for depression ( A. T. Beck et al., 1979 ) unless patients presented with comorbid personality disorder. For these patients, the treatment included adaptations of cognitive therapy for personality disorders, with an increased focus on patients' core beliefs and maladaptive behavioral strategies ( A. T. Beck & Freeman, 1990 ; Young, 1994 ). Eighteen (11%) patients were taking adjunctive antidepressant medication.

At the completion of therapy, patients' charts were reviewed to gather data concerning adjunctive treatment, length of treatment, and treatment outcome (e.g., diagnosis at discharge, general functioning, and depressive symptoms).

Measures Personality Belief Questionnaire.

The Personality Belief Questionnaire (PBQ; A. T. Beck & Beck, 1991 ) is a 126—item self-report measure developed to assess the beliefs associated with personality disorders. The scales and item content of the PBQ map onto nine of the DSM-IV personality disorders. A sample item from the

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Avoidant scale is, "Other people are potentially critical, indifferent, demeaning, or rejecting." Patients rate their endorsement of items from 0 ( I don't believe it at all ) to 4 ( I believe it totally ). The PBQ total scores range from 0 to 56 for each scale.

The PBQ scales have both high internal consistency (range .77—.93) and high test—retest reliability (range .63—.81) in nonclinical and clinical samples ( Trull, Goodwin, Schopp, Hillenbrand, & Schuster, 1993 ; A. T. Beck et al., 2000 ). In a heterogeneous sample of psychiatric outpatients, all of the patients with a personality disorder scored significantly higher on their criterion PBQ subscale than psychiatric patients who did not have a personality disorder diagnosis ( A. T. Beck et al., 2000 ). The evidence for the discriminant validity of specific scales was good for the Avoidant, Dependent, and Obsessive— Compulsive scales, and adequate for the Paranoid and Narcissistic scales ( A. T. Beck et al., 2000 ). That is to say, the Paranoid and Narcissistic scales appeared to overlap with other belief clusters more than the Avoidant, Obsessive—Compulsive, and Dependent scales. 2

Beck Depression Inventory–II.

The Beck Depression Inventory–II (BDI—II; Beck, Steer, & Brown, 1996 ) is a 21—item self-report instrument developed to measure severity of depression.

Structured Clinical Interview for DSM—IV.

The Structured Clinical Interview for DSM—IV (SCID—I, First et al., 1995a ; SCID—II, First et al., 1994 ) is a diagnostic instrument based on DSM—IV diagnostic criteria for Axis I and Axis II psychiatric disorders ( American Psychiatric Association, 1994 ). The reliability of SCID—II diagnoses is reported as good to fair ( First et al., 1995b ), and interrater agreement and test—retest reliability for presence of any Axis II disorder tends to be good–more consistently so when joint interviews are conducted (e.g., Arntz et al., 1992 ; O'Boyle & Self, 1990 ). In previous SCID reliability studies at the CCT, an overall kappa of .72 was reported ( Riskind, Beck, Berchick, Brown, & Steer, 1987 ).

Results

Background Characteristics

Before testing the study's main hypotheses, any systematic relationships between the background variables (demographic, psychiatric history, psychiatric, and treatment), independent variables (personality disorder and beliefs), and dependent variables (depression severity and global functioning) were explored. Of these variables, only age was systematically related to the independent variables (i.e., patients with a personality disorder were younger, M = 32.91, SD = 11.44, than patients without a personality disorder, M = 39.42, SD = 13.67, F (1, 121) = 6.10, p < .05, and younger patients reported more avoidant beliefs than older patients ( r = −.20, p < .05). However, age was not significantly associated with any outcome variable. To establish whether the competence of therapists in this study might affect the main research questions, two partial correlations between rated therapist competence and treatment outcome (BDI—II and global assessment of functioning [GAF]), partialling symptoms at intake, were computed. These suggest that therapist competence was not associated with the main − outcome measures (BDI—II r p = .08, N = 159; GAF r p = .13, N = 116). Therapist competence was therefore not included in subsequent analyses.

Personality Disorder Status and Treatment Outcome

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To examine whether a diagnosis of personality disorder affected outcome in cognitive therapy, two independent repeated measures and between-subjects analysis of covariance (ANCOVA) analyses were computed. For each analysis, the dependent variables were BDI—II and GAF scores at intake and termination. The independent variable was personality disorder status (absent or present), and the covariates were prescribed adjunctive medication and number of therapy sessions. The change in symptom severity over time was significant for both self-rated depression severity, Wilks's Λ F (1, 105) = 40.87, p < .001, and clinician-rated global functioning, Wilks's Λ F (1, 72) = 12.61, p < .05. However, the comparison of outcome by personality disorder status was not significant in either ANCOVA analysis. Examination of descriptive data ( Table 1 ) and between subjects effects, F (1, 105) = 3.87, p = .05, suggested a nonsignificant trend that patients with personality disorder reported more depressive symptomatology than patients without a personality disorder.

To examine the possibility that amount of comorbidity on Axis I and Axis II, as opposed to the presence or absence of a personality disorder, might negatively influence treatment outcome, two further ANCOVAs were computed with comorbidity as the independent variable (one, two, or three, or more additional Axes I and II diagnoses). The change in symptom severity over time was significant for self- rated depression severity, Wilks's Λ F (1, 103) = 35.09, p < .001, and clinician-rated global functioning, Wilks's Λ F (1, 70) = 7.14, p < .01. However, the outcome by comorbidity effect was not significant in either ANCOVA analysis, F < 1. Examination of descriptive data ( Table 2 ) and between-subjects effects, F (3, 103) = 5.29, p < .01, suggests that patients with greater comorbidity reported more depressive symptomatology.

PBQ Scales and Treatment Outcome

As displayed in Table 3 , Pearson correlations were computed between the PBQ scales, background variables (i.e., age and number of treatment sessions), predictive variables, and outcome variables.

Two hierarchical regression equations were constructed to examine whether maladaptive beliefs predicted change in the severity of depression over the course of treatment. The equations were built on conceptual (predictive belief variables hypothesized to predict residual symptoms after treatment) and statistical grounds (only predictive variables found to be significantly associated with the dependent variable in the Pearson correlations were entered). In the first regression equation, the dependent variable was BDI—II at termination. The PBQ Avoidant scale, but not the PBQ Dependent scale, predicted change in depressive symptoms over the course of treatment when initial levels of depressive severity were controlled ( Table 4 ). In a second regression analysis involving the GAF, the overall equation explained 43% of the variance in termination GAF, with initial GAF, β = .53, t (96) = 6.24, p β < .001, r p = .52); number of cognitive therapy sessions, = .33, t (96) = 3.93, p < .001, r p = .38; and β − − − the PBQ Paranoid scale, = .22, t (96) = 2.36, p < .05, r p = .24, being significant predictive variables. Avoidant and dependent beliefs were not significant predictors of GAF scores at termination in the final regression equation. 3

Discussion

This study of 162 depressed outpatients found that avoidant and paranoid beliefs are associated with treatment outcome. This finding is consistent with some recent findings that circumscribed maladaptive beliefs affect change over the course of cognitive therapy ( Blatt, Quinlan, Pilkonis, & Shea, 1995 ; Ilardi, Craighead, & Evans, 1997 ) and suggests that it is important to next ask, Which beliefs predict response to treatment, and through what mechanisms? This is underscored by the finding that dependent, obsessive—compulsive, and narcissistic beliefs did not predict response to cognitive therapy.

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Furthermore, our findings challenge the contention that patients with depression and personality disorder benefit less from cognitive therapy than depressed patients without a personality disorder ( Perry et al., 1999 ; Shea et al., 1990 ). Instead, the results of the present study indicate that depressed patients with more complex depression (i.e., presence of a personality disorder and greater comorbidity) who are treated with altered forms of cognitive therapy show significant improvements, comparable to patients with less complex depression. 4 However, patients with more complex depression report more severe depressive symptomatology at intake and more residual symptoms at termination.

There are several possible explanations for conflicting findings about the effectiveness of cognitive therapy for depressed patients with and without a personality disorder. Effectiveness studies in clinical settings with high external validity (e.g., the present study and Persons et al., 1988 ) show comparable outcomes for patients with and without a personality disorder, whereas randomized controlled trials (e.g., Shea et al., 1990 ) suggest that patients with a personality disorder respond less favorably. This is true even though the changes in depression scores across these efficacy and effectiveness studies are comparable. It is possible that patients with personality disorders would benefit from the structure of cognitive therapy, but they may benefit more when treatment extends beyond that found in manuals for Axis I depression ( A. T. Beck et al., 1979 ), to include elements for patients with comorbid personality disorders ( A. T. Beck & Freeman, 1990 ). In addition, the Collaborative Study found that the main difference in outcome for depressed patients with and without a personality disorder was on social functioning measures ( Shea et al., 1990 ), a dimension of outcome measured in this study only through the GAF. It is possible that if we had explicitly assessed social functioning, the groups would have differed in outcome, and future research might usefully include such outcome measures. Finally, the present study included a measure of therapist competence, which suggests that well-trained, highly supervised, and competent cognitive therapists conducted the therapy. There was not enough variance in our measure of therapist competence to ask whether therapist competence moderated outcome for more complex cases, a question that further research might usefully answer.

These findings raise several theoretical issues. The fact that avoidant beliefs predict some of the variance in improvement in depressive symptoms suggests some moderating role of these beliefs in the change process. The fact that avoidant beliefs predict changes in self-reported depressive symptoms and paranoid beliefs predict changes in therapist-rated general functioning suggests that different clusters of maladaptive beliefs affect change in different areas, presumably through different mechanisms. On the basis of several cognitive therapy case studies, Tang and DeRubeis (1999) have argued that significant change in patients' maladaptive beliefs predate improvements in depressive symptoms. Cognitive theory of personality disorder suggests that competent cognitive therapists are able to identify and intervene with patients' maladaptive beliefs and behaviors in the early stages of therapy, thereby explaining the comparable improvements across the groups with and without a personality disorder.

If this explanation is correct, the question remains, however: Why do avoidant and paranoid beliefs appear to negatively affect improvements in depressive symptoms during cognitive therapy? There are several possible answers. First, patients reporting many avoidant and paranoid beliefs may comply less with therapy because these beliefs interfere with homework assignments, an aspect of cognitive therapy that has consistently been associated with improved outcome (e.g., Detweiler & Whisman, 1999 ). Second, the in-session and between-sessions behaviors of these patients may adversely affect a therapists' ability to provide effective interventions. Third, patients with avoidant and paranoid beliefs may find it particularly difficult to form a therapeutic relationship that will enable the work of cognitive therapy to take place.

This study raises a number of policy and clinical implications for the treatment of depression. When well-trained and well-supervised cognitive therapists deliver cognitive therapy, patients with depression

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and complex comorbid problems are treatable through adapted cognitive therapy for depression. Furthermore, an assessment of patients' cognitive and behavioral avoidance may be useful in informing therapists about the likely response to cognitive therapy and in adapting interventions to specifically target these beliefs and behaviors ( Newman, 1998 ; Shea, Widiger, & Klein, 1992 ). This point is underscored by research suggesting that residual depression can be treated by skillfully delivered cognitive therapy ( Paykel et al., 1999 ).

Finally, it is important to note some conceptual and methodological issues that affect the interpretation of these findings. First, this study was not a randomized controlled trial, and therefore, any changes observed over time cannot definitively be attributed to cognitive therapy. Second, the sample was restricted to depressed patients, and the findings may be specific to depression. Third, although both general functioning GAF and symptom (BDI—II) outcome measures were used, other outcome measures may yield somewhat different estimates of outcome. Further work could usefully attempt to replicate the findings by using analogous personality functioning and outcome measures. Fourth, this study did not follow up patients after termination. Given that depressed patients who respond to cognitive therapy go on to relapse at high rates ( Ilardi et al., 1997 ), it is important to establish whether the current pattern of findings is maintained at follow-up. Finally, although the SCID—II is a standardized, structured procedure, and our interview was carried out by postdoctoral clinicians that were trained on the SCID—II, we do not have interrater reliability data on the Axis II diagnoses.

In summary, this study suggests the appropriateness of cognitive therapy for patients with a personality disorder ( A. T. Beck & Freeman, 1990 ; Young, 1994 ). Furthermore, an assessment of patients' constellations of maladaptive beliefs, particularly avoidant and paranoid beliefs, is indicated at assessment as prognostic indicators and can help therapists adapt interventions appropriately. Further work might usefully address the mechanism whereby avoidant and paranoid beliefs affect therapy outcome, and adapt and evaluate cognitive therapy interventions accordingly.

References

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Clark, D. A., Beck, A. T. & with Alford, B. A. (1999). Scientific foundations of cognitive theory and therapy of depression. (New York: Wiley) DeRubeis, R. J. & Crits-Christoph, P. (1998). Empirically supported individual and group psychological treatments for adult mental disorders. Journal of Consulting and Clinical Psychology, 66, 37-52. Detweiler, J. B. & Whisman, M. A. (1999). The role of homework assignments in cognitive therapy for depression: Potential methods for enhancing adherence. Clinical Psychology: Science and Practice, 6, 267-282. Elkin, I., Shea, M. T., Watkins, J. T., Imber, S. D., Sotsky, S. M., Collins, J. F., Glass, D. R., Pilkonis, P. A., Leber, W. R., Docherty, J. P., Fiester, S. J. & Parloff, M. B. (1989). National Institute of Mental Health Treatment of Depression Collaborative Research Program: General effectiveness of treatments. Archives of General Psychiatry, 46, 971-982. Evans, M. D., Hollon, S. D., DeRubeis, R. J., Piasecki, J. M., Grove, W. M., Garvey, M. J. & Tuason, V. B. (1992). Differential relapse following cognitive therapy and pharmacotherapy for depression. Archives of General Psychiatry, 49, 802-808. First, M. B., Spitzer, R. L., Gibbon, M. & Williams, J. B. W. (1995a). Structured Clinical Interview for (DSM—IV: Axis I disorder with psychotic screen. New York: New York Psychiatric Institute.) First, M. B., Spitzer, R. L., Gibbon, M. & Williams, J. B. W. (1995b). The Structured Clinical Interview for DMS—III—R Personality Disorders (SCID—II). Part I: Description. Journal of Personality Disorders, 9, 83-91. First, M. B., Spitzer, R. L., Gibbon, M., Williams, J. B. W. & Benjamin, L. (1994). Structured Clinical Interview for (DSM—IV Axis-II personality disorders (SCID—II, Version 2.0). New York: New York State Psychiatric Institute.) Hardy, G. E., Barkham, M., Shapiro, D. A., Stiles, W. B., Rees, A. & Reynolds, S. (1995). Impact of Cluster C personality disorders on outcomes of contrasting brief psychotherapies for depression. Journal of Consulting and Clinical Psychology, 63, 997-1004. Ilardi, S. S. & Craighead, W. E. (1999). The relationship between personality pathology and dysfunctional cognitions in previously depressed adults. Journal of Abnormal Psychology, 108, 51-57.

Ilardi, S. S., Craighead, W. E. & Evans, D. D. (1997). Modeling relapse in unipolar depression: The effects of dysfunctional cognitions and personality disorders. Journal of Consulting and Clinical Psychology, 65, 381-391. Kuyken, W. (2000). The role of therapist competence in a naturalistic study of cognitive therapy outcome. (Manuscript submitted for publication) Newman, C. F. (1998). Showing up for your own life: Cognitive therapy of avoidant personality disorder. In Session: Psychotherapy in Practice, 4, 55-71. O'Boyle, M. & Self, D. (1990). A comparison of two interviews for DSM—III—R personality disorders. Psychiatric Research, 32, 85-92. Paykel, E. S., Scott, J., Teasdale, J. D., Johnson, A. L., Garland, A., Moore, R., Jenaway, A., Cornwall, P. L., Hayhurst, H., Abbott, R. & Pope, M. (1999). Prevention of relapse in residual depression by cognitive therapy: A controlled trial. Archives of General Psychiatry, 56, 829-835. Perry, J. C., Banon, E. & Ianni, F. (1999). Effectiveness of psychotherapy for personality disorders. American Journal of Psychiatry, 156, 1312-1321. Persons, J. B., Burns, D. D. & Perloff, J. M. (1988). Predictors of dropout in cognitive therapy for depression in a private practice setting. Cognitive Therapy and Research, 12, 557-575. Pilkonis, P. A. & Frank, E. (1988). Personality pathology in recurrent depression: Nature, prevalence, and relationship to treatment response. American Journal of Psychiatry, 145, 435-441. Pretzer, J. & Beck, A. T. (1996). A cognitive theory of personality disorders.(In J. Clarkin (Ed.), Major theories of personality disorder (pp. 36—105). New York: Guilford Press.) Riskind, J. H., Beck, A. T., Berchick, R. J., Brown, G. & Steer, R. A. (1987). Reliability of DSM—III (diagnoses for major depression and generalized anxiety disorder using the Structured Clinical Interview for DSM—III. Archives of General Psychiatry, 44, 817—820.)

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Sato, T., Sakado, K., Sato, S. & Morikawa, T. (1994). Cluster A personality disorder: A marker of worse treatment outcome in major depression? Psychiatry Research, 53, 153-159. Scott, J. (1996). Cognitive therapy of affective disorders: A review. Journal of Affective Disorders, 37, 1-11. Shea, M. T., Pilkonis, P. A., Beckham, E., Collins, J. F., Elkin, I., Sotsky, S. M. & Docherty, J. P. (1990). Personality disorders and treatment outcome in the NIMH Treatment of Depression Collaborative Research Program. Archives of General Psychiatry, 147, 711-718. Shea, M. T., Widiger, T. A. & Klein, M. H. (1992). Comorbidity of personality disorders and depression: Implications for treatment. Journal of Consulting and Clinical Psychology, 60, 857-868. Tabachnick, B. G. & Fidell, L. S. (1996). Using multivariate statistics ((3rd ed.). New York: Harper & Row) Tang, T. Z. & DeRubeis, R. J. (1999). Reconsidering rapid early response in cognitive behavioral therapy. Clinical Psychology: Science and Practice, 6, 283-288. Trull, T. J., Goodwin, A. H., Schopp, L. H., Hillenbrand, T. L. & Schuster, T. (1993). Psychometric properties of a cognitive measure of personality disorders. Journal of Personality Assessment, 61, 536- 546. Young, J. E. (1994). Cognitive therapy for the personality disorders: A schema-focused approach ((Rev. ed.). Sarasota, FL: Professional Resource Press) Zimmerman, M. (1994). Diagnosing personality disorders. Archives of General Psychiatry, 51, 225-245.

Zuroff, D. C., Blatt, S. J., Sanislow, C. A., Bondi, C. M. & Pilkonis, P. A. (1999). Vulnerability to depression: Reexamining state dependence and relative stability. Journal of Abnormal Psychology, 108, 76-89.

The "deferred" category was used when the clinical interview did not permit a conclusive personality disorder diagnosis but there was sufficient evidence to suggest that their therapist should assess patients further during cognitive therapy. It was not always possible to establish from the chart review whether therapists had made definitive subsequent diagnoses. Exploratory analyses of the psychiatric characteristics (i.e., severity of psychopathology and psychiatric history) of patients with a deferred personality disorder classification suggest that they fall between those with and without a personality disorder. For analyses addressing hypotheses about the presence or absence of a personality disorder, a conservative strategy was adopted whereby patients with a deferred classification were omitted. For 17 patients (11%), the diagnosticians failed to record an Axis II diagnosis.

Because the PBQ has been validated only in general psychiatric outpatient populations, we conducted tests of its reliability and discriminant validity in the current data set. In the present study, the internal consistency of the Avoidant, Dependent, Obsessive—Compulsive, Narcissistic, and Paranoid scales was substantial (Cronbach alpha .86, .86, .88, .84, and .93 respectively). To establish the discriminant validity of the PBQ scales, a multivariate analysis of variance (MANOVA), with the independent variable being the relevant Axis II diagnoses (five levels) and the dependent variables being the five relevant PBQ scales (Avoidant, Dependent, Obsessive—Compulsive, Narcissistic, and Paranoid), was conducted and found to be significant, Wilks's lambda, F (5, 119) = 26.88, p < .0001. Furthermore, if individual PBQ scales are valid measures of their respective personality disorder diagnostic categories, patients with a specific personality disorder can be predicted to score higher on the corresponding PBQ scale than patients with alternative personality disorders or no personality disorder. One-way ANOVAs

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were conducted on each PBQ scale to test for overall group differences. Two of the three univariate F tests were significant: avoidant, F (1, 137) = 7.17, p < .01; dependent, F (1, 134) = 4.29, p < .05; obsessive—compulsive, F (1, 138) < 1. Only three patients were diagnosed with paranoid and narcissistic personality disorder; therefore, no test of discriminant validity in this depressed sample could be justified. It can be argued that the PBQ item content overlaps with depressive symptoms (e.g., self-worth and social withdrawal). Therefore, tests of discriminant validity were repeated, introducing BDI—II as a covariate. The pattern of findings of significant differences for all analyses was unchanged, suggesting that the discriminant validity of the PBQ total scores and PBQ Avoidant and Dependent scales was independent of depression severity.

Given that our sample of outpatients did not include patients with primary schizoid, schizotypal, or antisocial personality disorder; that the PBQ does not have a borderline scale; and that there are insufficient data attesting to the validity of the Histrionic scale, we used only the Avoidant, Dependent, Obsessive—Compulsive, Paranoid, and Narcissistic PBQ scales.

To address collinearity problems of including several intercorrelated PBQ scales in the same equation, collinearity statistics were computed for both regression equations. These were in the acceptable range ( Tabachnick & Fidell, 1996 ).

Note that cognitive therapy was delivered on an individualized basis so that all patients were treated with cognitive therapy that was adapted to their presenting problems.

We thank Cory F. Newman, the University of Pennsylvania Center for Cognitive Therapy therapists, and Rebecca L. Levine. Correspondence may be addressed to Willem Kuyken, School of Psychology, University of Exeter, Exeter, England, EX4 4QG. Electronic mail may be sent to [email protected] Received: April 24, 2000 Revised: November 3, 2000 Accepted: November 20, 2000

Table 1. Psychiatric Status of Patients With and Without Personality Disorder at Intake and Termination

Table 2. Psychiatric Status of Patients With and Without Comorbidity at Intake and Termination

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Table 3. Correlations Among Demographic, Personality Beliefs, Treatment, and Outcome Variables

Table 4. Hierarchical Regression Analyses on Depression Severity at Termination During Cognitive Therapy

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