رفتاردرمانی شناختی برای اختلال اضطراب اجتماعی فراگیر در نوجوانان: مطالعه کنترل شده تصادفی

Abstract Early identification and treatment of social anxiety disorder (SAD) is critical to prevent development of a chronic course of symptoms, persistent functional impairment, and progressive psychiatric comorbidity. A small but growing literature supports the effectiveness of cognitive behavior therapy (CBT) for anxiety disorders, including SAD, in adolescence. The present randomized controlled trial evaluated the efficacy of group vs. individual CBT for adolescents with generalized SAD in relation to an educational/supportive psychotherapy that did not contain specific CBT elements. All three treatments were associated with significant reductions in symptoms and functional impairment, and in improved social skills. No differences between treatments emerged on measures of symptoms, but the CBT conditions demonstrated greater gains on behavioral measures. The implications of the findings are discussed.

2. Results 2.1. Preliminary analyses 2.1.1. Sample severity The overall severity of the current sample was examined by comparing it to the clinical sample described in Beidel et al. (1995). A Student t-test revealed that pre-treatment SPAI-C scores were significantly higher in the current sample (M = 39.7, S.D. = 16.8) compared to the Beidel et al. clinical sample (M = 21.8, S.D. = 8.5, t = 8.64, d.f. = 65, p < .001). The difference found was not surprising given that all patients in the current sample were diagnosed with the generalized subtype of SAD, and we utilized minimal subject exclusion criteria. Also, an independent samples t-test revealed no significant difference between male and female pre-treatment SPAI-C scores in the current sample (p > .05), which was consistent with the findings of Beidel et al. 2.1.2. Preliminary group comparisons ANOVAs and post hoc tests revealed no pre-treatment group differences on study measures, age, grade level, or number of sessions attended (ps > .05) (see Table 1). Chi square analyses revealed no significant differences between the groups on any of the categorical variables, including gender, race/ethnicity, parental marriage status, follow-up treatments received (i.e., non-study related psychiatric treatment obtained between post-treatment and 6-month follow-up periods), homework completed, or concurrent psychiatric medication usage during the study (all ps > .05). 2.1.3. Treatment credibility The treatment conditions were compared on expectancy for improvement based on participants’ initial assessment of treatment credibility using the Reaction to Treatment Questionnaire (RTQ) total score. This measure was completed after the treatment rationale was explained to participants in the first session. A one-way ANOVA showed that the groups did not differ in their assessment of treatment credibility or expectancy for improvement from treatment (F = 0.14, d.f. = 2, 51, p = .87). 2.1.4. Treatment fidelity Treatment fidelity was assessed by having independent raters review audio tapes of sessions and rate whether or not various treatment components were covered using standardized rating forms. For example, during session one of I-CBT, raters assessed whether or not the therapist assigned breathing retraining homework according to the prescribed schedule (i.e., 10 min/2 times daily). Approximately 25% of I-CBT, G-CBT, and PST sessions were randomly selected for review, stratified by treatment time point (i.e., early, middle, or late). The number of items correctly covered in sessions was divided by the total number of items assessed to obtain a summary score. Treatment fidelity was excellent: G-CBT = 97%, I-CBT = 100%, and PST = 100%. 2.1.5. Study attrition A chi square test revealed no differences in drop out rates between groups (I-CBT n = 6 or 26%, G-CBT n = 6 or 27%, PST n = 4 or 17%, p > .05). Furthermore, no differences in missing follow-up data between groups were identified (I-CBT n = 4 or 24%, G-CBT n = 3 or 19%, PST n = 4 or 21%, p > .05). Finally, no significant differences were found between those who dropped out or had missing follow-up data and those with complete data on any study variables (all ps > .05). 2.2. Overall group change Descriptive statistics for study measures are presented in Table 2. First, analyses were conducted to test for overall group change, regardless of treatment (i.e., null models), as well as the presence of significant within group variability in change. Table 2. Estimated means and standard deviations for outcome measures by treatment condition Measures I-CBT (n = 23) G-CBT (n = 22) PST (n = 23) M S.D. M S.D. M S.D. Self-Report SPAI-C Pretest 43.27 16.96 36.86 19.48 38.87 13.99 Posttest 32.47 19.08 33.40 14.72 34.34 16.26 Follow-up 32.21 20.77 24.23 17.47 29.78 13.89 SAS-C Pretest 58.43 17.73 58.32 15.64 55.36 15.28 Posttest 50.29 17.81 53.81 14.17 48.90 16.63 Follow-up 50.18 15.21 43.62 16.48 46.44 14.71 Parent Report SAS-P Pretest 61.55 17.16 67.15 9.42 60.83 14.79 Posttest 62.87 16.15 58.73 14.25 55.53 15.55 Follow-up 57.40 18.32 61.08 12.88 47.00 14.21 Clinician-Rated CGI Pretest 5.05 1.00 4.68 .84 4.55 .67 Posttest 3.13 1.55 3.47 1.64 3.63 1.42 Follow-up 3.27 1.49 2.38 1.26 2.71 1.59 Behavioral Role Play Test a SUDS (1-100) Pretest 57.06 22.04 49.29 19.83 55.78 22.89 Posttest 32.49 19.82 47.14 24.58 44.17 20.23 Follow-up 29.35 14.10 35.85 18.09 34.42 21.79 Self-Ratings of Performance Pretest 2.09 .87 2.72 .74 2.42 .69 Posttest 3.49 .77 3.33 .88 2.81 .62 Follow-up 3.31 .50 3.38 .83 2.69 .95 Observer Social Skills Ratings Pretest 2.50 .98 2.31 .59 2.22 .75 Posttest 3.00 .92 2.74 .94 2.76 .83 Follow-up 3.23 .77 3.36 1.01 2.44 .54 Note: I-CBT, Individual Cognitive Behavior Therapy; G-CBT, Group Cognitive Behavior Therapy; PST, Psychoeducational-Supportive Therapy; SPAI-C, Social Phobia and Anxiety Inventory-Child Version; SAS-C/P, Social Anxiety Scale-Child/Parent Version; CGI, Clinical Global Impression Scale; SUDS, Subjective Units of Distress Scale; M, mean; S.D., standard deviation. a Average of 3 role play tasks. Table options 2.2.1. Symptom severity measures Participants showed a significant decrease over time in social anxiety symptoms, as measured by the SPAI-C from baseline through follow-up (γ10 = −4.87, t = −4.39, d.f. = 66, p < .001, d = 1.08). The degree of variability of SPAI-C decline was significant (μ1 = 205.35, χ2 = 409.73, p < .001), indicating differentiation in score change across individuals. We examined the SAS-C and also found a significant decline over time (γ10 = −4.94, t = −4.60, d.f. = 65, p < .001, d = 1.14), as well as significant variability (μ1 = 177.50, χ2 = 378.34, p < .001). The SAS-P showed a significant overall decline over time from baseline to follow-up (γ10 = −0.01, t = −3.00, d.f. = 62, p = .004, d = .76), though it did not show significant variability (μ1 < .01, χ2 = 32.66, p > .50), suggesting that individual decline did not vary across participants. A significant linear decrease over time was demonstrated in CGI-S ratings, as reported by clinicians (γ10 = −1.05, t = −8.84, d.f. = 66, p < .001, d = 2.18). Again, a significant variability was observed (μ1 = 104, χ2 = 144.26, p < .001). 2.2.2. Behavioral assessment measures Regardless of condition, participants’ self-ratings of their performance in role play assessments increased over time (γ10 = 0.38, t = 5.07, d.f. = 61, p < .001, d = 1.30), with significant variability across individuals (μ1 = 0.19, χ2 = 119.26, p < .001). Participants’ average role play SUDS ratings across time points significantly decreased, regardless of condition (γ10 = −11.01, t = −5.91, d.f. = 61, p < .001, d = 1.51), with significant variability across individuals (μ1 = 163.91, χ2 = 147.29, p < .001). Lastly, average observer rated social skills showed an increase over time (γ10 = 0.36, t = 4.77, d.f. = 48, p < .001, d = 1.38), with significant variability across individuals (μ1 = 0.37, χ2 = 181.66, p < .001). 2.3. Primary treatment comparisons Analyses of the overall sample showed a pattern of symptom reduction and functional enhancement over the course of treatment, across a variety of domains, including self-report data, parent report data, and observational ratings from blind assessors. Notably, significant variability was shown among individuals on most measures. The following analyses examined whether individual response differences could be related to treatment condition. Our primary hypothesis was that CBT (regardless of delivery format) would produce greater improvement on outcome measures compared to PST.1 2.3.1. Severity measures Despite overall reduction in social anxiety symptoms as measured by the SPAI-C, results did not show a significant relationship between symptom decline and treatment condition (γ11 = 1.37, t = 0.64, d.f. = 65, p = .522, d = .16). Also, no significant difference was found for treatment condition on the SAS-P total score (t = −0.98, d.f. = 61, p = .33, d = .25) nor on the SAS-C total score (t = 1.02, d.f. = 64, p = .31, d = .26). Finally, no significant differences were shown between conditions over time in CGI-Severity, t = 0.52, d.f. = 66, p = .649, d = .13. 2.3.2. Behavioral assessment measures Behavioral assessment ratings of subjective overall performance in role plays over time showed a significant relation to treatment condition, t = −2.30, d.f. = 60, p = .023, d = .59, with those in the CBT conditions reporting significantly greater improvement compared to those in PST across time points. No significant difference in average SUDS role plays ratings was found between CBT and PST participants over time, t = −0.05, d.f. = 60, p = .963, d = .01. Lastly, those in CBT had significantly greater improvement in observer-rated social skills in role plays over time compared to those in PST, t = −2.01, d.f. = 47, p = .047, d = .59. 2.4. Secondary analyses The secondary analyses were conducted to examine potential group differences among the three treatment conditions. These analyses are considered exploratory given the smaller cell sizes. To facilitate between group comparisons among the three conditions, we dichotomously dummy coded treatment by creating the following variables: Individual CBT (0 = no, 1 = yes), Group CBT (0 = no, 1 = yes), and PST (0 = no, 1 = yes). PST served as the control condition when I-CBT and G-CBT were used as main factors (i.e., I-CBT = 0 and G-CBT = 0 represented PST) and G-CBT served as the control condition to facilitate comparison between CBT conditions (i.e., I-CBT = 0 and PST = 0 represented G-CBT). 2.4.1. Symptom severity measures Results showed non-significant findings for the three treatment group differences over time on the SPAI-C. Further, there was no difference between treatment conditions on the SAS-C and SAS-P total scores. In addition, results showed no significant differences in CGI-Severity score over time according to condition (all ps > .05). 2.4.2. Behavioral assessment measures Significantly greater change over time in average self-rating in role play performance was found between PST and I-CBT (γ11 = 0.47, t = 3.06, d.f. = 59, p = .003, d = .80), suggesting those in I-CBT showed greater improvement. There was no difference between PST vs. G-CBT or I-CBT vs. G-CBT on this measure. Additionally, a significant difference over time was found between I-CBT and G-CBT, with those in I-CBT reporting a lower SUDS over time for the role plays, t = −2.03, d.f. = 59, p = .044, d = .53. There was no significant difference between PST and either CBT condition in change in SUDS ratings. Finally, no significant differences were found between conditions in average social skills ratings across time; although it appeared the trend of greater improvement in G-CBT approached significance as compared to the PST condition, t = −.84, d.f. = 46, p = .068, d = .25. 2.5. Recovery rates The clinical significance of treatment gains was determined by calculating percentages of patients in each condition who no longer met criteria for social phobia at post-treatment and follow-up. These analyses were conducted using the subsample of completers with available data. Based on the criteria used by Beidel et al. (2000a) and Beidel et al. (2000b), patients were designated as recovered if they met both of the following criteria: (1) SPAI-C total score <18 (social phobia diagnostic cutoff score established by Beidel et al., 1995), and (2) CGI rating <4 (below diagnostic threshold based on severity and functional impairment). At post-treatment, there were no significant differences between recovery rates for the I-CBT (29%, n = 5), G-CBT (27%, n = 3), and PST (16%, n = 3) conditions (p > .05). However, there was a significant difference between I-CBT (15%, n = 2), G-CBT (54%, n = 7), and PST (19%, n = 3) at follow-up (χ2 = 5.93, d.f. = 2, p = .05), with higher recovery rates for the G-CBT condition; see Fig. 2. Proportion of patients recovered following treatment. Fig. 2. Proportion of patients recovered following treatment.