(PS9-D76) Predictors and Moderators of Outcome in Indicated School-based CBT for Youth with Anxiety

Meta-analyses of school-based CBT indicated prevention programs for anxiety typically report small but significant effects. The majority of indicated CBT interventions for anxiety delivered in schools comprises 8 to 12 sessions. Brief CBT is commonly defined as having sessions reduced by at least 50% compared to standard treatment. Currently, there are very limited data regarding which youth may benefit most and which may benefit least from indicated prevention for anxiety and characteristics of youth who respond differentially to interventions of different intensity (brief vs. standard length CBT). Offering Brief indicated CBT could be a more efficient use of resources as not all youth may need the standard more intensive intervention.

 

The present study examined predictors and moderators of treatment outcome among 302 youth (mean age 14.0 years, SD .8, 84 % female), with anxiety who participated in a randomized waitlist-controlled trial comparing two school-based 10-weeks CBT group interventions. The interventions were a standard-length intervention (10 session, 15 hours) and a brief intervention (5 session,  5.5 hours). Groups consisted of 5 to 8 youth, and most of the group leaders were school nurses. The interventions were delivered in school during school hours. Potential predictors included baseline demographic, child, and parent factors, and intervention was examined as a moderation effect on outcome. Outcomes were youth- and parent-rated youth reduction of anxiety (SCAS- c/p) and depressive (SMFQ- c/p) symptoms at post-intervention and at 1-year follow-up, and clinician rated severity (CGI-S) at post-intervention.

 

A small number of significant predictors were found across different informants, focusing on different aspects of outcome. The most consistent findings were that i) higher pre-intervention impairment from anxiety predicted larger change, but youth with high pre-intervention symptom levels still had higher impairment at post-intervention compared to youth with low pre-intervention impairment, ii) higher caregiver strain was associated with less favorable outcomes, and iii) higher parent rated treatment credibility and expectancy was associated with improved outcome at post-intervention. At 1-year follow-up, no consistent significant predictors of outcome were identified. The estimated mean change, demonstrated a reduction at post-intervention of -7.29 (SE[E]) = 4.32, p = .09) for SCAS-c, and -7.85 (SE[E]) = .68, p < .001 for SCAS-p. For SMFQ- c/p, the corresponding numbers were -1.68 (SE[E]) = .42, p < .001)  and -4.69 (SE[E]) = .41, p < .001, respectively. For CGI-S, the estimated mean change was -.91, (SE[E]) = .08, p = < .001. Response across the outcomes were not moderated by program intensity.

 

The study’s design provided an opportunity to examine pre-intervention factors predictive of outcome generally with indicated school-based CBT for youth with anxiety, and to help identify whether program intensity moderated outcome in this group of youth. The results of the present study identified a small number of key pre-intervention variables in relation to CBT outcome in general, but no variables that could inform the choice of CBT format despite increasing interest in brief forms of CBT delivery.