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Brief cognitive-behavioral versus nondirective therapy for panic disorder
I 13%120.
J. Beimv. Ther. & Exp. Psychiar. Vol. 26, No. 2. pp. 1995. Copyright 0 1995 Elsewer Science Ltd Fnnted m Great Britain. All rights reserved 0005s79lhN5 $9.50 + 0 no
ooo5-7916(95)oooo3-8
BRIEF COGNITIVE-BEHAVIORAL VERSUS NONDIRECTIVE THERAPY FOR PANIC DISORDER MICHELLE
G. CRASKE,
EMANUEL University
MAIDENBERG of California,
and ALEXANDER
BYSTRITSKY
Los Angeles
Summary - Thirty panic disorder patients were assigned randomly to four weekly sessions ot either cognitive-behavioral therapy or nondirective, supportive therapy. Dependent variables included clinician ratings, standardized self-report questionnaires, and self-monitoring. Cognitive-behavioral therapy led to significant reductions in worry about the recurrence of panic, and in overall ratings of phobic distress. Nondirective supportive therapy did not produce significant effects. In addition, proportionately more patients who were actively panicking at preassessment and underwent cognitive-behavioral treatment were free of panic after treatment. More than one third (38%) of patients who received cognitive-behavioral treatment were sufficiently improved that they withdrew from the pharmacological trial and/or did not meet criteria for panic disorder by the end of the four weeks.
Research to date has clearly demonstrated the efficacy of cognitive-behavioral treatments (CBT) for panic disorder (e.g., Barlow, Craske, Cemy, & Klosko, 1989; Beck, Sokol, Clark, Berchick, & Wright, 1992; Clark, Salkovskis, Hackmann, Middleton, Anastasiades, & Gelder, 1994; Ost, 1988). Overall, from 85 to 100% of patients are free of panic immediately after CBT, and at follow-up two years later. Research has shown CBT for panic disorder to be more effective than the passage of time alone and applied relaxation (Barlow et al., 1989; Clark et al., 1994), and nondirective supportive psychotherapy (Beck et al., 1992). On the other hand, Shear, Pilonis, Cloitre, and Leon (1994) found that a nondirective treatment was as effective as CBT. Treatment outcome research efforts currently address mechanisms of therapeutic change (e.g., Clark et al., 1994; Amtz, Hildebrand, & van den Hout, 1994), relative efficacies of specific
Requests for reprints should be addressed Angeles, CA 90024-1563, U.S.A.
to Michelle
therapeutic components (e.g., Beck, Stanley, Baldwin, Deagle, & Averill, 1994), and cost efficiency and availability (e.g., Cote, Gauthier, Laberge, Cormier, & Plamondon, 1994; Gould, Clum, & Shapiro, 1993; Lidren, Watkins, Gould, Clum, Asterino, & Tulloch, 1994). Cost efficiency and availability are important given that only 40% of a community sample of individuals suffering from panic and agoraphobia reportedly received treatment of any type (Pollard, Henderson, Frank, & Margolis, 1989). Also, only 12-18% of a sample of almost 800 individuals responding to advertising for panic disorder had received behavioral treatment (in vivo exposure, relaxation or hypnosis, or a combination) (Taylor et al., 1989). In contrast, 54-62% had received psychotropic medications. These results suggest limited cost efficiency and/or availability of CBT. In the long-term, CBT is probably less costly than pharmacotherapy, given the high rates of
G. Craske,
113
Department
of Psychology,
UCLA, 405 Hilgard
Ave.. Los
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MICHELLE
G. CRASKE et al.
relapse upon attempted medication withdrawal (estimated 70-90%; Fyer et al., 1987) and the likely return to medication regimes for prolonged durations (30-60% do not complete medication tapering; e.g., Noyes, Garvey, Cook, & Suelzer, 1991; Pecknold, Swinson, Kuch, & Lewin, 1988). In contrast, clinical status tends to maintain or improve, on average, following completion of CBT (e.g., Clark et al., 1994; Craske, Brown, & Barlow, 1991; Ost, 1988). However, the short-term costs of 12-16 weekly, 60 minute sessions (the typical CBT format in the studies cited earlier) may be financially prohibitive for the patient, and/or overly time-consuming for professionals with long waiting lists or restrictions on number of patient visits. Earlier research examined cost efficient means of delivering behavior therapy for agoraphobia with some success. For example, Ghosh and Marks (1987) found that computer-assisted and self-help formats for in vivo exposure therapy were as effective as clinician-directed in vivo exposure. Mathews, Gelder, and Johnston (1981), Mathews, Teasdale, Munby, Johnston, and Shaw (1977), and Jannoun, Munby, Catalan, and Gelder (1980) reported marked improvements in agoraphobia from homebased in vivo exposure practice with the aid of bibliotherapy and limited therapist contact. On the other hand, Holden, O’Brien, Barlow, Stetson, and Infantino (1983) found that self-help procedures were of limited value for the more severely housebound agoraphobic patient. More recently, Gould et al. (1993) found that bibliotherapy and self-help treatment was as effective as therapistdelivered CBT for panic disorder. Similarly, Lidren et al. (1994) found that eight weeks of bibliotherapy were as effective as eight weeks of group therapy for panic disorder. Finally, Cote et al. (1994) found no differences between minimal and full therapist contact in the delivery of CBT for panic disorder over 17 weeks. The current study evaluated a cost-efficient approach to CBT for panic disorder by comparing four sessions of CBT to nondirective, supportive therapy. These brief treatments were delivered to a sample of patients seeking pharmacotherapy for their anxiety problem.
Method Design The study was a 2 (treatment) x 2 (assessment) mixed design. Treatments were cognitivebehavioral therapy (CBT) versus nondirective supportive therapy (NST). Treatment assignment was random. Assessments were at pre- and posttreatment. Subjects Subjects were individuals seeking treatment for panic disorder, who responded to advertising or were self- or other-referred to the Anxiety Program at the Neuropsychiatric Institute of UCLA, which is recognized as a primarily pharmacologically oriented treatment and research center. All subjects were screened for eligibility for a pharmacological trial. Inclusion criteria included: aged between 18 and 65; a principal diagnosis of panic disorder with or without agoraphobia (PD/A), assigned from administration of the Structured Clinical Interview for DSM-III-R (SCID; Spitzer & Williams, 1986) and the panic disorder and agoraphobia sections of the Anxiety Disorders Interview Schedule-Revised (ADIS-R; DiNardo & Barlow, 1988); willingness to random assignment to 17 weeks or either placebo or varying dosage regimes of a psychoactive medication (i.e., Klonopin); and successful withdrawal from psychotropic medications for at least 7 days prior to initial diagnostic evaluation. Exclusion criteria included: hypersensitivity to benzodiazapines; diagnoses of organic disorders, obsessive-compulsive disorder, psychoses, bipolar disorder, adjustment disorder, and current (within the last 6 months) substance abuse/dependence; suicidality; and serious medical conditions. The SCID and ADIS-R structured interviews generally yield highly reliable PD/A diagnoses (Manuzza et al., 1989; DiNardo, Moras, Barlow, Rapee, & Brown, 1993). Diagnostic reliability statistics were not available for the current sample. Diagnoses were made by clinic staff, and verified by a psychiatrist who met briefly with each patient.
Brief Therapy for Panic
Subjects were offered 4 weeks of CBT or NST prior to entering the medication trial. Four of 34 eligible subjects refused. The final sample included 20 females and 10 males, whose average age was 36.1 yrs (SD = 11.0; range = 21-57). The average duration of the problem was 9.9 yrs (SD = 9.3; range = l-38). Twenty-three percent were diagnosed without agoraphobia, and 67% with agoraphobia. Ethnic composition was as follows: 24 participants were White, four were Hispanic, one was Asian, and one was African-American. Fifty-six percent believed in biological causes for their panic disorder, and 84% endorsed likely psychological cases (these two categories were not mutually exclusive). Four percent expressed preference for pharmacotherapy as the sole treatment option, 20% preferred psychotherapy as the sole treatment option, and 76% preferred the combination. Twenty-eight percent had received psychological treatment, and 62% received psychotropic medication, in the past (28% had not received prior treatment). Finally, 27% withdrew from medications before entering the study. Measures Clinician ratings. The panic disorder and agoraphobia sections of the ADIS-R (DiNardo & Barlow, 1988) were administered at preand post-assessment by an independent evaluator. Specifically we analysed the degree of worry over the recurrence of panic (O-g-point scale), and number of agoraphobic situations avoided at least mildly. These items were referenced to the preceding week. Self-report questionnaires. A battery of standardized questionnaires was administered. These included measures specific to panic disorder: Anxiety Sensitivity Index (Reiss, Peterson, Gursky & McNally, 1986) which is a dispositional measure of the tendency to misinterpret bodily sensations as harmful; and the Fear Questionnaire (Marks & Mathews, 1979) that includes subscales of fearfulness of agoraphobic situations, social situations, and blood/injury situations, a misery/depression scale, and a self-
11s
rating of phobic distress. General distress measures included: the Four Dimensional Anxiety (Bystritsky, 1990) that provides a sum index of anxiety symptomatology and subscales for emotional, physiological, cognitive and behavioral anxiety; and the Subjective Symptoms Scale (Hafner & Marks, 1976) which measures interference in work, social life, home management, family, and leisure activities, due to panic disorder. Self-monitoring. Subjects recorded panic attacks as they occurred, using Panic Attack Records (Rapee, Craske, & Barlow, 1990). In addition, subjects self-monitored the following at the end of each day: maximum anxiety (O-8), average depression (O-8), and average worry about, or level of preoccupation with, panicking (O-8). Self-monitoring was ongoing for 10 days to 2 weeks at each assessment. Treatments and Therapists Treatments were matched in terms of therapist contact; four 60-90 minute, weekly individual therapy sessions conducted within the NPI Anxiety Program. Therapists for CBT were a nurse and PhD psychologist (E.M.). Therapists for NST were two psychiatrists. All therapists were specialized in the treatment of anxiety disorders with approximately three years of experience. Treatment integrity was addressed via manualized treatments, and ongoing therapy supervision, with review and feedback of approximately 25% of audiotapes of treatment sessions by the principal author. Cognitive-behavior therapy (CBT). CBT represented a condensed version of the exposure-cognitive treatment condition in the Barlow et al. (1989) study. The first session provided education about the nature of anxiety and panic, and the physiology underlying panic attack symptoms, to correct misappraisals of symptoms as being indicative of danger. Also, basic principles of cognitive restructuring were introduced. Session 2 continued cognitive
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restructuring, and introduced breathing retraining with in-session practice. Session 3 continued cognitive restructuring and introduced interoceptive exposure with in-session practice. Session 4 reviewed the concepts and skills of the preceding three sessions. Subjects were given written summaries of each session, and’ were assigned between-session practices of cognitive restructuring, breathing retraining, and interoceptive exposure. Nondirective supportive therapy (NST). NST was modelled on the nonprescriptive therapy condition described by Shear et al. (1994). The same information as provided to CBT subjects was provided in session 1 of NST. Thereafter, sessions 211 focused on nondirective discussion to anxiety and panic symptoms, and their possible relationship with daily life stressors. Therapists were instructed to provide a supportive environment, listening and reflecting to the client, without identifying specific psychological themes, etc. In addition, therapists were instructed to remain nondirective if behavioral coping methods were suggested by the patient, so that the therapist neither actively discouraged or encouraged, but stated “its up to you to do what you feel ready to do”.
Results Completers vs Drop-Outs Sixteen subjects were assigned randomly to CBT, and 14 to NST. One subject dropped out from NST, none dropped out from CBT. Pre-Assessment Dijferences CBT (N = 16) and NST (N = 13) completers were compared on pre-assessment demographics, and dependent measures, using Fisher’s exact tests and independent t-tests. The groups did not differ. The average number of treatment sessions attended was 3.5 (SD = 0.9) for CBT subjects and 3.1 (SD = 1 .O) for NST subjects.
Pre- to Post-Treatment Efsects Pre- to post-treatment differences were compared between CBT and NST groups using 2 (Treatment; CBT vs NST) x 2 (Assessment; prevs post-treatment) mixed univariate analyses of variance (ANOVAs). A univariate approach was chosen given the limited power of multivariate statistics with current cell sizes, and their failure to capture the common desynchrony among dependent variables. Clinician ratings. Means and standard deviations are shown in Table 1. The average degree of worry over panic produced significant main effects of Treatment, F( 1,19) = 5.2, p c .05, and Assessment, F(1,19) = 12.5, p c .Ol, as well as a significant interaction of Treatment x Assessment, F( 1,19) = 6.8, p c .02. Simple effects analyses of the interaction showed that CBT subjects reported less worry at post-assessment in comparison to pre-assessment, t(9) = 3.6, p < .Ol, whereas worry ratings did not change over time for NST subjects. The number of agoraphobic situations rated by the interviewer as avoided did not change over time nor differ between groups. Self-report questionnaires. Means and standard deviations are shown in Table 1. Anxiety Sensitivity Index scores did not reduce significantly over time nor differ between groups. Two subscales of the Fear Questionnaire produced significant results. The Treatment x Assessment interaction was significant for the social phobia subscale, F( 1,19) = 4.3, p c .05. However, differences were not found in simple effects analyses of this interaction. Also, the interaction effect was significant for self-rating of phobic distress, F(1,20) = 4.7, p < .05. Simple effects of the interaction showed that self-ratings reduced from pre- to post-assessment for CBT subjects, t(l0) = 4.5, p < .OOl, whereas they did not change for NST subjects. No significant differences were obtained from the blood/injury phobia, agoraphobia, or misery/depression subscales of the Fear Questionnaire. In terms of measures of general distress, the
117
Brief Therapy for Panic Table 1
Means of Diagnostic and Self-Report Measures From Pre- to Post-Assessment in CBT and NST Groups: Standard Deviations Presented in Parentheses CBT (N = 16)
ADIS-R measures Worry about panic Number of agoraphobia
situations
Self-report measures Anxiety sensitivity Fear Questionnaire - Agoraphobia -
Social
-
Blood/injury
-
Misery/depression
-
Self-rating
Four-Dimensional
Anxiety scale
Subjective Symptoms
Scale
Pre
5.7
3.3
(1.8) 5.4 (5.2)
(2.0) 6.0 (4.4)
6.3 (2.1) 5.9 (5.7)
5.9* (4.6) 5.9 (4.6)
26.7 (17.7)
24.1 (12.6)
39.4 (14.2)
35.5 (12.8)
15.6 (15.3) 12.5 (10.5) 9.2 (11.4) 14.0 (10.2) 5.8
12.0 (12.3) 9.6
19.3 (9.4) 8.8
(7.4) 6.4 (7.3) 12.1
(6.8) 14.0 (10.1) 20.3 (12.1) 5.8 (2.0) 104.8 (33.0) 24.1 (9.5)
(1.8) 87.9 (27.9) 18.3 (I 1.7)
Four-Dimensional Anxiety Scale yielded a significant main effect of Assessment, F( 1,23) = 8.5, p < .Ol. However, there were no group effects. Finally, there were no main or interaction effects for Subjective Symptoms Scale scores. Self-monitoring. Means and standard deviations are shown in Table 2. Fifty-three percent of CBT subjects reported they did not experience panic attacks at post-assessment, in comparison to 23% of NST subjects (several missing data points were replaced by estimates of panic frequency recorded during the ADIS-R). A Fisher’s exact test did not yield a significant difference. Daily ratings of anxiety, depression, and worry about panic did not differ over time nor between groups. Clinically signijkant
Clinical
change
significance
was defined
NST (N= 13) Post
Post
Pre
in two ways.
(9.5) 3.6 (2.2) 78.1 (22.5) 15.7 (10.6)
17.8 (10.2) 10.8’ (6.6) 12.8 (9.2) 16.8 (8.9) 5.0* (2.0) 87.7 (19.1) 20.3 (8.9)
First, significant change in each major outcome measure was defined as follows: self-monitored one or more panic attacks at pre, and zero panic attacks at post; ADIS-R rating of worry about panic reduced from pre to post, and less than or equal to 3 at post; ADIS-R number of agoraphobia situations avoided reduced from pre to post; Anxiety Sensitivity Index scores reduced from pre to post, and less than or equal to 27 at post; and average interference with functioning from the Subjective Symptoms Scale reduced from pre to post, and less than or equal to 3 at post. The percentages of each group that met these criteria are presented in Figure 1. Fisher’s exact tests showed that more CBT subjects met the panic attack criterion, x2(1) = 6.7, p < .Ol, and worry about panic criterion, x2(1) = 5.4, p < .02, than NST subjects. Second, clinical significance was defined as the number of subjects who, after completion of
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MICHELLE
G. CRASKE et al.
Table 2 Means of Self-Monitored Measures From Pre- to Post-Assessment in CBT and NST Groups; Standard Deviations Presented in Parentheses CBT (N = 16)
Panic frequency
per week
Daily anxiety Daily depression
Post
Pre
4.1 (4.8) 4.5 (2.2) 2.4 (2.8)
0.6 (0.6) 3.5 (2.3) 2.0 (1.7) 3.1 (2.2)
3.0 (3.9) 3.5 (2.1) 2.7 (1.6) 5.1 (1.5)
Daily worry about panic
therapy, (1) declined to enter the medication trial because they no longer wanted treatment, and/or (2) did not meet criteria for panic disorder and therefore were not eligible for the medication trial. This occurred for six (38%) CBT subjects and one (7.7%) NST subject. Test of proportions approached significance, Z = 1.9, p < .07.
Within the CBT group, subjects actively panicking at pre-assessment and free of panic at post-assessment (i.e., responders, N = 8) were compared to remaining CBT subjects (i.e., nonresponders, N = 7), in terms of pre-assessment measures. signillcant
improvement
loo-
80-
60-
4Q-
ZO-
0’
panic OCBT
13) Post 2.2 (1.8) 3.3 (1.9) 2.2 (1.7) 4.5 (1.8)
Using a series of independent sample t-tests, responders were found to rate lower levels of phobic distress, t( 13) = 2.1, p = .05; means were 4.4 (SD = 1.4) versus 6.3 (SD = 2.1). In addition, responders reported fewer panic attacks, but the effects were nullified by high variability within the nonresponder group; means were 2.1 (SD = 1.6) versus 6.4 (SD = 6.4). Similarly, responders reported less interference with functioning means were 13.1 (SD = 20.1) versus 20.1 (SD = 15.2) - and less anxiety symptomatology on the Four Dimensional Scale - means were 76.5 (SD = 14.0) versus 101.0 (SD = 34.8) - but group differences were mitigated by heterogenity within the nonresponder group and small cell sizes. When two outliners were excluded from the nonresponder group, responders were found to
Predictors of response to treatment
, clInically
NST(N=
Pre
BNST
Figure 1.
II9
Brief Therapy for Panic
report less distress on self-rating of phobic distress, fear of social and agoraphobic situations, and interference with functioning.
Discussion Three main conclusions can be drawn from this study. First, four weekly sessions of CBT were more effective than four weekly sessions of nondirective, supportive therapy in this patient sample, in terms of panic, worry about panic, and phobic fear. However, the superior efficacy of CBT did not generalize to measures of general distress or interference with functioning. Preliminary analyses suggested a trend for the less distressed individual to respond most favorably to a brief CBT intervention. This result parallels the finding that self-directed in vivo exposure (another means of enhancing cost efficiency of CBT) is of little benefit for severely agoraphobic patients (Holden et al., 1983). Conversely, initial severity of distress does not predict outcome from therapist-delivered, lengthier CBT (Craske et al., 1991). However, conclusions regarding the relationship between initial severity level and treatment outcome are limited by small cell sizes in the current study. Second, brief CBT may be a viable and sufficient treatment option for a subset of panic disorder patients who attend medically oriented settings, given that 38% of the CBT group were sufficiently improved to decline pharmacotherapy and/or no longer met criteria for panic disorder. These results suggest the value of educating those patients seeking medication about CBT approaches, and the provision of CBT as a first treatment option. Additional CBT and/or pharmacotherapy might proceed for the patient who does not respond to CBT within a relatively short period of time. Note that this approach contrasts with typical clinical practice, in which medication is the usual first course of action that may or may not be followed by CBT or other psychotherapies. Third, while four weeks of CBT was somewhat effective, the outcome was considerably less than
is typically achieved from 12 to 16 weeks of CBT. More extensive bibliotherapy and homework assignments, plus reviewing audiotapes of treatment sessions, may enhance the effectiveness of brief CBT. On the other hand, the current sample was possible less likely to respond favorably to CBT than samples in the studies cited earlier. Twenty-seven percent of the sample was withdrawn from medications prior to entering CBT, whereas medication regimes are usually continued throughout CBT. Also, a large majority of the current sample preferred a medication treatment approach (either alone or in combination with psychotherapy), and all had responded to advertising for a medication trial or had self referred to a primarily medically oriented treatment center. In contrast, patients in the studies cited earlier were seeking psychological treatment. The efficacy of lengthier CBT in this type of sample warrants further investigation. In contrast to the advantages offered by CBT in the current study, Shear et al. (1994) found that it was no more effective than supportive therapy when each was conducted over IS sessions. It is conceivable that lengthier treatment may have yielded comparable treatment effects in the current study. However, the finding that CBT is an option for a subgroup of panic disorder patients, in contrast to the ineffectiveness of four weeks of supportive therapy, has important clinical implications. References Arntz, A., Hildebrand, M., & van den Hout. M. ( 1994). Overprediction of anxiety, and disconfirmatory processes, in anxiety disorders. Behaviour Resenrc-h md Thertrpy. 32, 109-122.
Barlow, d. H., Craske, M. G., Cerny. J. A., & Klosko. J. S. (1989). Behavioral treatment of panic disorder. Behavior Therapy,
20.261-282.
Beck, A. T., Sokol, L., Clark, D. A., Berchick, R.. & Wright, F. (1992). A crossover study of focused cognitive therapy for panic disorder. American Journtrl of P sychiofrv. 149. 778-783.
Beck, J. G., Stanley, M. A., Baldwin, L. E., Deagle, E. A., CG Averill, P. M. (1994). Comparison of cognitive therapy and relaxation training for panic disorder. Journa/ of Consrr//ing and Clinical Psychology, 62, 818-826. Bystritsky, A. (1990). Development of a multidimensional scale of anxiety. Journal ofAnxir& Lkwrdrrs. 4, 99-l IS.
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Clark, D. M., Salkovskis, P. M., Hackmann, A., Middleton, H., Anastasiades, P., & Gelder, M. (1994). A comparison of cognitive therapy, applied relaxation and imipramine in the treatment of panic disorder. British Journal of Psychiatry, 164,759-769. Cote, G., Gauthier, J. G., Laberge, B., Cormier, H. J., & Plamondon, J. (1994). Reduced therapist contract in the cognitive-behavioral treatment of panic disorder. Behavior Therapy, 25, 123-145. Craske, M. G., Brown, T. A., & Barlow, D. H. (1991). Behavioral treatment of panic disorder: a two-year followup. Behavior Therapy, 22,289-304. DiNardo, P. A., & Barlow, D. H. (1988). Anxiety Disorders Interview Schedule-Revised (ADS-R). New York: Phobia and Anxiety Disorders Clinic, The University at Albany, State University of New York. DiNardo, P. A., Moras, K., Rapee, R., Barlow, D. H., & Brown, T. A. (1993). Reliability of DSM-III-R anxiety disorder categories using the Anxiety Disorders Interview Schedule - Revised (ADIS-R). Archives of General Psychiatry, j&251-256. Fyer, A., Liebowitz, M., Gorman, J., Campeces, R., Levin, A., Davies, S., Moetz, D., & Klein, D. (1987). Discontinuation of alprazolam treatment in panic patients. American Journal of Psychiatry, 144,303-308. Ghosh, A., & Marks, I. M. (1987). Self-treatment of agoraphobia by exposure. Behavior Therapy, 18.3-16. Gould, R. A., Clum, G. A., & Shapiro, D. (1993). The use of bibliotherapy in the treatment of panic: a preliminary investigation. Behavior Therapy, 24, 241-252. Hafner, R., & Marks, 1. (1976). Exposure in vivo of agoraphobics: contributions of diazapem, group exposure and anxiety evocation. Psychological Medicine, 6,71-88. Holden, A. E., O’Brien, G. T., Barlow, D. H., Stetson, D., & Infantino, A. (1983). Self-help manual for agoraphobia: a preliminary report of effectiveness. Behavior Therapy, 14, 545-556. Jannoun, L., Munby, M., Catalan, J., & Gelder, M. (1980). A home-based treatment program for agoraphobia: replication and controlled evaluation. Behavior Therapy, 11,294-305. Lidren, D. M., Watkins, P. L., Gould, R. A., Clum, R. A., Asterino, M., & Tulloch, H. L. (1994). A comparison of bibliotherapy and group therapy in the treatment of panic disorder. Journal of Consulfing & Clinical Psychology, 62, 865-869.
Mannuzza, S., Fyer, A. J., Martin, L. Y., Gallops, M. S., Endicott, J., Gorman, J., Liebowitz, M. R., & Klein, D. F. (1989). Reliability of anxiety assessment: diagnostic agreement. Archives ofGeneral Psychiatry, 46, 1093-l 101. Marks, I., & Mathews, A. M. (1979). Brief standard self-rating for phobic patients. Behavior Research and Therapy, 17, 263-267. Mathews, A. M., Gelder, M., & Johnston, D. W. (1981). Agoraphobia: nature and treatment. New York: Guilford Press. Mathews, A. M., Teasdale, J., Munby, M., Johnston, D., & Shaw, P. (1977). A home-based treatment program for agoraphobia. Behavior Therapy, 8,915-924. McNamee, G., O’Sullivan, G., Lelliott, & Marks, I. (1989). Telephone-guided treatment for housebound agoraphobics with panic disorder: exposure vs. relaxation. Behavior Therapy, 20.491497. Noyes, R., Garvey, M. J., Cook, B., & Suelzer, M. (1991). Controlled discontinuation of benzodiazepine treatment for patients with panic disorder. American Journal of Psychiatry, 148,517-523. Ost, L.-G. (1988). Applied relaxation vs. progressive relaxation in the treatment of panic disorder. Behaviour Research and Therapy, 26, 13-22. Pollard, C. E., Henderson, G., Frank, M., & Margolis, R. B. (1989). Help-seeking patterns of anxiety-disordered individuals in the general population. Journal of Anxiery Disorders, 3, 131-138. Rapee, R. M., Craske, M. G., & Barlow, D. H. (1990). Subject described features of panic attacks using a new selfmonitoring form. Journal of Anxiety Disorders, 4, 17 l-l 8 1. Reiss, S., Peterson, R., Gursky, D., & McNally, R. (1986). Anxiety sensitivity, anxiety frequency, and the prediction of fearfulness. Behaviour Research and Therapy, 24, l-8. Shear, M. K., Pilkonis, P. A., Cloitre, M., & Leon, A. C. (1994). Cognitive behavioral treatment compared with nonprescriptive treatment of panic disorder. Archives of General Psychiatry, 51,395401. Spitzer, R. L., & Williams, J. B. (1986). Structured clinical interview for DSM-III-R. New York: Biometrics Research Department, New York State Psychiatric Institute. Taylor, C. B., King, R., Margraf, J., Ehlers, A., Telch, M., Roth, W. T., & Agras, W. S. (1989). Use of medication and in vivo exposure in volunteers for panic disorder research. American Journal of Psychiatry, 146, 1423-1426.
J. Beimv. Ther. & Exp. Psychiar. Vol. 26, No. 2. pp. 1995. Copyright 0 1995 Elsewer Science Ltd Fnnted m Great Britain. All rights reserved 0005s79lhN5 $9.50 + 0 no
ooo5-7916(95)oooo3-8
BRIEF COGNITIVE-BEHAVIORAL VERSUS NONDIRECTIVE THERAPY FOR PANIC DISORDER MICHELLE
G. CRASKE,
EMANUEL University
MAIDENBERG of California,
and ALEXANDER
BYSTRITSKY
Los Angeles
Summary - Thirty panic disorder patients were assigned randomly to four weekly sessions ot either cognitive-behavioral therapy or nondirective, supportive therapy. Dependent variables included clinician ratings, standardized self-report questionnaires, and self-monitoring. Cognitive-behavioral therapy led to significant reductions in worry about the recurrence of panic, and in overall ratings of phobic distress. Nondirective supportive therapy did not produce significant effects. In addition, proportionately more patients who were actively panicking at preassessment and underwent cognitive-behavioral treatment were free of panic after treatment. More than one third (38%) of patients who received cognitive-behavioral treatment were sufficiently improved that they withdrew from the pharmacological trial and/or did not meet criteria for panic disorder by the end of the four weeks.
Research to date has clearly demonstrated the efficacy of cognitive-behavioral treatments (CBT) for panic disorder (e.g., Barlow, Craske, Cemy, & Klosko, 1989; Beck, Sokol, Clark, Berchick, & Wright, 1992; Clark, Salkovskis, Hackmann, Middleton, Anastasiades, & Gelder, 1994; Ost, 1988). Overall, from 85 to 100% of patients are free of panic immediately after CBT, and at follow-up two years later. Research has shown CBT for panic disorder to be more effective than the passage of time alone and applied relaxation (Barlow et al., 1989; Clark et al., 1994), and nondirective supportive psychotherapy (Beck et al., 1992). On the other hand, Shear, Pilonis, Cloitre, and Leon (1994) found that a nondirective treatment was as effective as CBT. Treatment outcome research efforts currently address mechanisms of therapeutic change (e.g., Clark et al., 1994; Amtz, Hildebrand, & van den Hout, 1994), relative efficacies of specific
Requests for reprints should be addressed Angeles, CA 90024-1563, U.S.A.
to Michelle
therapeutic components (e.g., Beck, Stanley, Baldwin, Deagle, & Averill, 1994), and cost efficiency and availability (e.g., Cote, Gauthier, Laberge, Cormier, & Plamondon, 1994; Gould, Clum, & Shapiro, 1993; Lidren, Watkins, Gould, Clum, Asterino, & Tulloch, 1994). Cost efficiency and availability are important given that only 40% of a community sample of individuals suffering from panic and agoraphobia reportedly received treatment of any type (Pollard, Henderson, Frank, & Margolis, 1989). Also, only 12-18% of a sample of almost 800 individuals responding to advertising for panic disorder had received behavioral treatment (in vivo exposure, relaxation or hypnosis, or a combination) (Taylor et al., 1989). In contrast, 54-62% had received psychotropic medications. These results suggest limited cost efficiency and/or availability of CBT. In the long-term, CBT is probably less costly than pharmacotherapy, given the high rates of
G. Craske,
113
Department
of Psychology,
UCLA, 405 Hilgard
Ave.. Los
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relapse upon attempted medication withdrawal (estimated 70-90%; Fyer et al., 1987) and the likely return to medication regimes for prolonged durations (30-60% do not complete medication tapering; e.g., Noyes, Garvey, Cook, & Suelzer, 1991; Pecknold, Swinson, Kuch, & Lewin, 1988). In contrast, clinical status tends to maintain or improve, on average, following completion of CBT (e.g., Clark et al., 1994; Craske, Brown, & Barlow, 1991; Ost, 1988). However, the short-term costs of 12-16 weekly, 60 minute sessions (the typical CBT format in the studies cited earlier) may be financially prohibitive for the patient, and/or overly time-consuming for professionals with long waiting lists or restrictions on number of patient visits. Earlier research examined cost efficient means of delivering behavior therapy for agoraphobia with some success. For example, Ghosh and Marks (1987) found that computer-assisted and self-help formats for in vivo exposure therapy were as effective as clinician-directed in vivo exposure. Mathews, Gelder, and Johnston (1981), Mathews, Teasdale, Munby, Johnston, and Shaw (1977), and Jannoun, Munby, Catalan, and Gelder (1980) reported marked improvements in agoraphobia from homebased in vivo exposure practice with the aid of bibliotherapy and limited therapist contact. On the other hand, Holden, O’Brien, Barlow, Stetson, and Infantino (1983) found that self-help procedures were of limited value for the more severely housebound agoraphobic patient. More recently, Gould et al. (1993) found that bibliotherapy and self-help treatment was as effective as therapistdelivered CBT for panic disorder. Similarly, Lidren et al. (1994) found that eight weeks of bibliotherapy were as effective as eight weeks of group therapy for panic disorder. Finally, Cote et al. (1994) found no differences between minimal and full therapist contact in the delivery of CBT for panic disorder over 17 weeks. The current study evaluated a cost-efficient approach to CBT for panic disorder by comparing four sessions of CBT to nondirective, supportive therapy. These brief treatments were delivered to a sample of patients seeking pharmacotherapy for their anxiety problem.
Method Design The study was a 2 (treatment) x 2 (assessment) mixed design. Treatments were cognitivebehavioral therapy (CBT) versus nondirective supportive therapy (NST). Treatment assignment was random. Assessments were at pre- and posttreatment. Subjects Subjects were individuals seeking treatment for panic disorder, who responded to advertising or were self- or other-referred to the Anxiety Program at the Neuropsychiatric Institute of UCLA, which is recognized as a primarily pharmacologically oriented treatment and research center. All subjects were screened for eligibility for a pharmacological trial. Inclusion criteria included: aged between 18 and 65; a principal diagnosis of panic disorder with or without agoraphobia (PD/A), assigned from administration of the Structured Clinical Interview for DSM-III-R (SCID; Spitzer & Williams, 1986) and the panic disorder and agoraphobia sections of the Anxiety Disorders Interview Schedule-Revised (ADIS-R; DiNardo & Barlow, 1988); willingness to random assignment to 17 weeks or either placebo or varying dosage regimes of a psychoactive medication (i.e., Klonopin); and successful withdrawal from psychotropic medications for at least 7 days prior to initial diagnostic evaluation. Exclusion criteria included: hypersensitivity to benzodiazapines; diagnoses of organic disorders, obsessive-compulsive disorder, psychoses, bipolar disorder, adjustment disorder, and current (within the last 6 months) substance abuse/dependence; suicidality; and serious medical conditions. The SCID and ADIS-R structured interviews generally yield highly reliable PD/A diagnoses (Manuzza et al., 1989; DiNardo, Moras, Barlow, Rapee, & Brown, 1993). Diagnostic reliability statistics were not available for the current sample. Diagnoses were made by clinic staff, and verified by a psychiatrist who met briefly with each patient.
Brief Therapy for Panic
Subjects were offered 4 weeks of CBT or NST prior to entering the medication trial. Four of 34 eligible subjects refused. The final sample included 20 females and 10 males, whose average age was 36.1 yrs (SD = 11.0; range = 21-57). The average duration of the problem was 9.9 yrs (SD = 9.3; range = l-38). Twenty-three percent were diagnosed without agoraphobia, and 67% with agoraphobia. Ethnic composition was as follows: 24 participants were White, four were Hispanic, one was Asian, and one was African-American. Fifty-six percent believed in biological causes for their panic disorder, and 84% endorsed likely psychological cases (these two categories were not mutually exclusive). Four percent expressed preference for pharmacotherapy as the sole treatment option, 20% preferred psychotherapy as the sole treatment option, and 76% preferred the combination. Twenty-eight percent had received psychological treatment, and 62% received psychotropic medication, in the past (28% had not received prior treatment). Finally, 27% withdrew from medications before entering the study. Measures Clinician ratings. The panic disorder and agoraphobia sections of the ADIS-R (DiNardo & Barlow, 1988) were administered at preand post-assessment by an independent evaluator. Specifically we analysed the degree of worry over the recurrence of panic (O-g-point scale), and number of agoraphobic situations avoided at least mildly. These items were referenced to the preceding week. Self-report questionnaires. A battery of standardized questionnaires was administered. These included measures specific to panic disorder: Anxiety Sensitivity Index (Reiss, Peterson, Gursky & McNally, 1986) which is a dispositional measure of the tendency to misinterpret bodily sensations as harmful; and the Fear Questionnaire (Marks & Mathews, 1979) that includes subscales of fearfulness of agoraphobic situations, social situations, and blood/injury situations, a misery/depression scale, and a self-
11s
rating of phobic distress. General distress measures included: the Four Dimensional Anxiety (Bystritsky, 1990) that provides a sum index of anxiety symptomatology and subscales for emotional, physiological, cognitive and behavioral anxiety; and the Subjective Symptoms Scale (Hafner & Marks, 1976) which measures interference in work, social life, home management, family, and leisure activities, due to panic disorder. Self-monitoring. Subjects recorded panic attacks as they occurred, using Panic Attack Records (Rapee, Craske, & Barlow, 1990). In addition, subjects self-monitored the following at the end of each day: maximum anxiety (O-8), average depression (O-8), and average worry about, or level of preoccupation with, panicking (O-8). Self-monitoring was ongoing for 10 days to 2 weeks at each assessment. Treatments and Therapists Treatments were matched in terms of therapist contact; four 60-90 minute, weekly individual therapy sessions conducted within the NPI Anxiety Program. Therapists for CBT were a nurse and PhD psychologist (E.M.). Therapists for NST were two psychiatrists. All therapists were specialized in the treatment of anxiety disorders with approximately three years of experience. Treatment integrity was addressed via manualized treatments, and ongoing therapy supervision, with review and feedback of approximately 25% of audiotapes of treatment sessions by the principal author. Cognitive-behavior therapy (CBT). CBT represented a condensed version of the exposure-cognitive treatment condition in the Barlow et al. (1989) study. The first session provided education about the nature of anxiety and panic, and the physiology underlying panic attack symptoms, to correct misappraisals of symptoms as being indicative of danger. Also, basic principles of cognitive restructuring were introduced. Session 2 continued cognitive
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restructuring, and introduced breathing retraining with in-session practice. Session 3 continued cognitive restructuring and introduced interoceptive exposure with in-session practice. Session 4 reviewed the concepts and skills of the preceding three sessions. Subjects were given written summaries of each session, and’ were assigned between-session practices of cognitive restructuring, breathing retraining, and interoceptive exposure. Nondirective supportive therapy (NST). NST was modelled on the nonprescriptive therapy condition described by Shear et al. (1994). The same information as provided to CBT subjects was provided in session 1 of NST. Thereafter, sessions 211 focused on nondirective discussion to anxiety and panic symptoms, and their possible relationship with daily life stressors. Therapists were instructed to provide a supportive environment, listening and reflecting to the client, without identifying specific psychological themes, etc. In addition, therapists were instructed to remain nondirective if behavioral coping methods were suggested by the patient, so that the therapist neither actively discouraged or encouraged, but stated “its up to you to do what you feel ready to do”.
Results Completers vs Drop-Outs Sixteen subjects were assigned randomly to CBT, and 14 to NST. One subject dropped out from NST, none dropped out from CBT. Pre-Assessment Dijferences CBT (N = 16) and NST (N = 13) completers were compared on pre-assessment demographics, and dependent measures, using Fisher’s exact tests and independent t-tests. The groups did not differ. The average number of treatment sessions attended was 3.5 (SD = 0.9) for CBT subjects and 3.1 (SD = 1 .O) for NST subjects.
Pre- to Post-Treatment Efsects Pre- to post-treatment differences were compared between CBT and NST groups using 2 (Treatment; CBT vs NST) x 2 (Assessment; prevs post-treatment) mixed univariate analyses of variance (ANOVAs). A univariate approach was chosen given the limited power of multivariate statistics with current cell sizes, and their failure to capture the common desynchrony among dependent variables. Clinician ratings. Means and standard deviations are shown in Table 1. The average degree of worry over panic produced significant main effects of Treatment, F( 1,19) = 5.2, p c .05, and Assessment, F(1,19) = 12.5, p c .Ol, as well as a significant interaction of Treatment x Assessment, F( 1,19) = 6.8, p c .02. Simple effects analyses of the interaction showed that CBT subjects reported less worry at post-assessment in comparison to pre-assessment, t(9) = 3.6, p < .Ol, whereas worry ratings did not change over time for NST subjects. The number of agoraphobic situations rated by the interviewer as avoided did not change over time nor differ between groups. Self-report questionnaires. Means and standard deviations are shown in Table 1. Anxiety Sensitivity Index scores did not reduce significantly over time nor differ between groups. Two subscales of the Fear Questionnaire produced significant results. The Treatment x Assessment interaction was significant for the social phobia subscale, F( 1,19) = 4.3, p c .05. However, differences were not found in simple effects analyses of this interaction. Also, the interaction effect was significant for self-rating of phobic distress, F(1,20) = 4.7, p < .05. Simple effects of the interaction showed that self-ratings reduced from pre- to post-assessment for CBT subjects, t(l0) = 4.5, p < .OOl, whereas they did not change for NST subjects. No significant differences were obtained from the blood/injury phobia, agoraphobia, or misery/depression subscales of the Fear Questionnaire. In terms of measures of general distress, the
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Brief Therapy for Panic Table 1
Means of Diagnostic and Self-Report Measures From Pre- to Post-Assessment in CBT and NST Groups: Standard Deviations Presented in Parentheses CBT (N = 16)
ADIS-R measures Worry about panic Number of agoraphobia
situations
Self-report measures Anxiety sensitivity Fear Questionnaire - Agoraphobia -
Social
-
Blood/injury
-
Misery/depression
-
Self-rating
Four-Dimensional
Anxiety scale
Subjective Symptoms
Scale
Pre
5.7
3.3
(1.8) 5.4 (5.2)
(2.0) 6.0 (4.4)
6.3 (2.1) 5.9 (5.7)
5.9* (4.6) 5.9 (4.6)
26.7 (17.7)
24.1 (12.6)
39.4 (14.2)
35.5 (12.8)
15.6 (15.3) 12.5 (10.5) 9.2 (11.4) 14.0 (10.2) 5.8
12.0 (12.3) 9.6
19.3 (9.4) 8.8
(7.4) 6.4 (7.3) 12.1
(6.8) 14.0 (10.1) 20.3 (12.1) 5.8 (2.0) 104.8 (33.0) 24.1 (9.5)
(1.8) 87.9 (27.9) 18.3 (I 1.7)
Four-Dimensional Anxiety Scale yielded a significant main effect of Assessment, F( 1,23) = 8.5, p < .Ol. However, there were no group effects. Finally, there were no main or interaction effects for Subjective Symptoms Scale scores. Self-monitoring. Means and standard deviations are shown in Table 2. Fifty-three percent of CBT subjects reported they did not experience panic attacks at post-assessment, in comparison to 23% of NST subjects (several missing data points were replaced by estimates of panic frequency recorded during the ADIS-R). A Fisher’s exact test did not yield a significant difference. Daily ratings of anxiety, depression, and worry about panic did not differ over time nor between groups. Clinically signijkant
Clinical
change
significance
was defined
NST (N= 13) Post
Post
Pre
in two ways.
(9.5) 3.6 (2.2) 78.1 (22.5) 15.7 (10.6)
17.8 (10.2) 10.8’ (6.6) 12.8 (9.2) 16.8 (8.9) 5.0* (2.0) 87.7 (19.1) 20.3 (8.9)
First, significant change in each major outcome measure was defined as follows: self-monitored one or more panic attacks at pre, and zero panic attacks at post; ADIS-R rating of worry about panic reduced from pre to post, and less than or equal to 3 at post; ADIS-R number of agoraphobia situations avoided reduced from pre to post; Anxiety Sensitivity Index scores reduced from pre to post, and less than or equal to 27 at post; and average interference with functioning from the Subjective Symptoms Scale reduced from pre to post, and less than or equal to 3 at post. The percentages of each group that met these criteria are presented in Figure 1. Fisher’s exact tests showed that more CBT subjects met the panic attack criterion, x2(1) = 6.7, p < .Ol, and worry about panic criterion, x2(1) = 5.4, p < .02, than NST subjects. Second, clinical significance was defined as the number of subjects who, after completion of
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Table 2 Means of Self-Monitored Measures From Pre- to Post-Assessment in CBT and NST Groups; Standard Deviations Presented in Parentheses CBT (N = 16)
Panic frequency
per week
Daily anxiety Daily depression
Post
Pre
4.1 (4.8) 4.5 (2.2) 2.4 (2.8)
0.6 (0.6) 3.5 (2.3) 2.0 (1.7) 3.1 (2.2)
3.0 (3.9) 3.5 (2.1) 2.7 (1.6) 5.1 (1.5)
Daily worry about panic
therapy, (1) declined to enter the medication trial because they no longer wanted treatment, and/or (2) did not meet criteria for panic disorder and therefore were not eligible for the medication trial. This occurred for six (38%) CBT subjects and one (7.7%) NST subject. Test of proportions approached significance, Z = 1.9, p < .07.
Within the CBT group, subjects actively panicking at pre-assessment and free of panic at post-assessment (i.e., responders, N = 8) were compared to remaining CBT subjects (i.e., nonresponders, N = 7), in terms of pre-assessment measures. signillcant
improvement
loo-
80-
60-
4Q-
ZO-
0’
panic OCBT
13) Post 2.2 (1.8) 3.3 (1.9) 2.2 (1.7) 4.5 (1.8)
Using a series of independent sample t-tests, responders were found to rate lower levels of phobic distress, t( 13) = 2.1, p = .05; means were 4.4 (SD = 1.4) versus 6.3 (SD = 2.1). In addition, responders reported fewer panic attacks, but the effects were nullified by high variability within the nonresponder group; means were 2.1 (SD = 1.6) versus 6.4 (SD = 6.4). Similarly, responders reported less interference with functioning means were 13.1 (SD = 20.1) versus 20.1 (SD = 15.2) - and less anxiety symptomatology on the Four Dimensional Scale - means were 76.5 (SD = 14.0) versus 101.0 (SD = 34.8) - but group differences were mitigated by heterogenity within the nonresponder group and small cell sizes. When two outliners were excluded from the nonresponder group, responders were found to
Predictors of response to treatment
, clInically
NST(N=
Pre
BNST
Figure 1.
II9
Brief Therapy for Panic
report less distress on self-rating of phobic distress, fear of social and agoraphobic situations, and interference with functioning.
Discussion Three main conclusions can be drawn from this study. First, four weekly sessions of CBT were more effective than four weekly sessions of nondirective, supportive therapy in this patient sample, in terms of panic, worry about panic, and phobic fear. However, the superior efficacy of CBT did not generalize to measures of general distress or interference with functioning. Preliminary analyses suggested a trend for the less distressed individual to respond most favorably to a brief CBT intervention. This result parallels the finding that self-directed in vivo exposure (another means of enhancing cost efficiency of CBT) is of little benefit for severely agoraphobic patients (Holden et al., 1983). Conversely, initial severity of distress does not predict outcome from therapist-delivered, lengthier CBT (Craske et al., 1991). However, conclusions regarding the relationship between initial severity level and treatment outcome are limited by small cell sizes in the current study. Second, brief CBT may be a viable and sufficient treatment option for a subset of panic disorder patients who attend medically oriented settings, given that 38% of the CBT group were sufficiently improved to decline pharmacotherapy and/or no longer met criteria for panic disorder. These results suggest the value of educating those patients seeking medication about CBT approaches, and the provision of CBT as a first treatment option. Additional CBT and/or pharmacotherapy might proceed for the patient who does not respond to CBT within a relatively short period of time. Note that this approach contrasts with typical clinical practice, in which medication is the usual first course of action that may or may not be followed by CBT or other psychotherapies. Third, while four weeks of CBT was somewhat effective, the outcome was considerably less than
is typically achieved from 12 to 16 weeks of CBT. More extensive bibliotherapy and homework assignments, plus reviewing audiotapes of treatment sessions, may enhance the effectiveness of brief CBT. On the other hand, the current sample was possible less likely to respond favorably to CBT than samples in the studies cited earlier. Twenty-seven percent of the sample was withdrawn from medications prior to entering CBT, whereas medication regimes are usually continued throughout CBT. Also, a large majority of the current sample preferred a medication treatment approach (either alone or in combination with psychotherapy), and all had responded to advertising for a medication trial or had self referred to a primarily medically oriented treatment center. In contrast, patients in the studies cited earlier were seeking psychological treatment. The efficacy of lengthier CBT in this type of sample warrants further investigation. In contrast to the advantages offered by CBT in the current study, Shear et al. (1994) found that it was no more effective than supportive therapy when each was conducted over IS sessions. It is conceivable that lengthier treatment may have yielded comparable treatment effects in the current study. However, the finding that CBT is an option for a subgroup of panic disorder patients, in contrast to the ineffectiveness of four weeks of supportive therapy, has important clinical implications. References Arntz, A., Hildebrand, M., & van den Hout. M. ( 1994). Overprediction of anxiety, and disconfirmatory processes, in anxiety disorders. Behaviour Resenrc-h md Thertrpy. 32, 109-122.
Barlow, d. H., Craske, M. G., Cerny. J. A., & Klosko. J. S. (1989). Behavioral treatment of panic disorder. Behavior Therapy,
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Beck, A. T., Sokol, L., Clark, D. A., Berchick, R.. & Wright, F. (1992). A crossover study of focused cognitive therapy for panic disorder. American Journtrl of P sychiofrv. 149. 778-783.
Beck, J. G., Stanley, M. A., Baldwin, L. E., Deagle, E. A., CG Averill, P. M. (1994). Comparison of cognitive therapy and relaxation training for panic disorder. Journa/ of Consrr//ing and Clinical Psychology, 62, 818-826. Bystritsky, A. (1990). Development of a multidimensional scale of anxiety. Journal ofAnxir& Lkwrdrrs. 4, 99-l IS.
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Clark, D. M., Salkovskis, P. M., Hackmann, A., Middleton, H., Anastasiades, P., & Gelder, M. (1994). A comparison of cognitive therapy, applied relaxation and imipramine in the treatment of panic disorder. British Journal of Psychiatry, 164,759-769. Cote, G., Gauthier, J. G., Laberge, B., Cormier, H. J., & Plamondon, J. (1994). Reduced therapist contract in the cognitive-behavioral treatment of panic disorder. Behavior Therapy, 25, 123-145. Craske, M. G., Brown, T. A., & Barlow, D. H. (1991). Behavioral treatment of panic disorder: a two-year followup. Behavior Therapy, 22,289-304. DiNardo, P. A., & Barlow, D. H. (1988). Anxiety Disorders Interview Schedule-Revised (ADS-R). New York: Phobia and Anxiety Disorders Clinic, The University at Albany, State University of New York. DiNardo, P. A., Moras, K., Rapee, R., Barlow, D. H., & Brown, T. A. (1993). Reliability of DSM-III-R anxiety disorder categories using the Anxiety Disorders Interview Schedule - Revised (ADIS-R). Archives of General Psychiatry, j&251-256. Fyer, A., Liebowitz, M., Gorman, J., Campeces, R., Levin, A., Davies, S., Moetz, D., & Klein, D. (1987). Discontinuation of alprazolam treatment in panic patients. American Journal of Psychiatry, 144,303-308. Ghosh, A., & Marks, I. M. (1987). Self-treatment of agoraphobia by exposure. Behavior Therapy, 18.3-16. Gould, R. A., Clum, G. A., & Shapiro, D. (1993). The use of bibliotherapy in the treatment of panic: a preliminary investigation. Behavior Therapy, 24, 241-252. Hafner, R., & Marks, 1. (1976). Exposure in vivo of agoraphobics: contributions of diazapem, group exposure and anxiety evocation. Psychological Medicine, 6,71-88. Holden, A. E., O’Brien, G. T., Barlow, D. H., Stetson, D., & Infantino, A. (1983). Self-help manual for agoraphobia: a preliminary report of effectiveness. Behavior Therapy, 14, 545-556. Jannoun, L., Munby, M., Catalan, J., & Gelder, M. (1980). A home-based treatment program for agoraphobia: replication and controlled evaluation. Behavior Therapy, 11,294-305. Lidren, D. M., Watkins, P. L., Gould, R. A., Clum, R. A., Asterino, M., & Tulloch, H. L. (1994). A comparison of bibliotherapy and group therapy in the treatment of panic disorder. Journal of Consulfing & Clinical Psychology, 62, 865-869.
Mannuzza, S., Fyer, A. J., Martin, L. Y., Gallops, M. S., Endicott, J., Gorman, J., Liebowitz, M. R., & Klein, D. F. (1989). Reliability of anxiety assessment: diagnostic agreement. Archives ofGeneral Psychiatry, 46, 1093-l 101. Marks, I., & Mathews, A. M. (1979). Brief standard self-rating for phobic patients. Behavior Research and Therapy, 17, 263-267. Mathews, A. M., Gelder, M., & Johnston, D. W. (1981). Agoraphobia: nature and treatment. New York: Guilford Press. Mathews, A. M., Teasdale, J., Munby, M., Johnston, D., & Shaw, P. (1977). A home-based treatment program for agoraphobia. Behavior Therapy, 8,915-924. McNamee, G., O’Sullivan, G., Lelliott, & Marks, I. (1989). Telephone-guided treatment for housebound agoraphobics with panic disorder: exposure vs. relaxation. Behavior Therapy, 20.491497. Noyes, R., Garvey, M. J., Cook, B., & Suelzer, M. (1991). Controlled discontinuation of benzodiazepine treatment for patients with panic disorder. American Journal of Psychiatry, 148,517-523. Ost, L.-G. (1988). Applied relaxation vs. progressive relaxation in the treatment of panic disorder. Behaviour Research and Therapy, 26, 13-22. Pollard, C. E., Henderson, G., Frank, M., & Margolis, R. B. (1989). Help-seeking patterns of anxiety-disordered individuals in the general population. Journal of Anxiery Disorders, 3, 131-138. Rapee, R. M., Craske, M. G., & Barlow, D. H. (1990). Subject described features of panic attacks using a new selfmonitoring form. Journal of Anxiety Disorders, 4, 17 l-l 8 1. Reiss, S., Peterson, R., Gursky, D., & McNally, R. (1986). Anxiety sensitivity, anxiety frequency, and the prediction of fearfulness. Behaviour Research and Therapy, 24, l-8. Shear, M. K., Pilkonis, P. A., Cloitre, M., & Leon, A. C. (1994). Cognitive behavioral treatment compared with nonprescriptive treatment of panic disorder. Archives of General Psychiatry, 51,395401. Spitzer, R. L., & Williams, J. B. (1986). Structured clinical interview for DSM-III-R. New York: Biometrics Research Department, New York State Psychiatric Institute. Taylor, C. B., King, R., Margraf, J., Ehlers, A., Telch, M., Roth, W. T., & Agras, W. S. (1989). Use of medication and in vivo exposure in volunteers for panic disorder research. American Journal of Psychiatry, 146, 1423-1426.