Long-Term Effectiveness of Cognitive Behavioral Therapy in Routine Outpatient Care for Youth with Anxiety Disorders

Introduction: This study examined the long-term effectiveness of cognitive behavioral therapy (CBT) (>= 2 years after the end of therapy) in the routine care of youth (mean 11.95 years; SD = 3.04 years) with primary anxiety disorder (AD). Methods: Two hundred and ten children with any AD as a primary diagnosis and with any comorbidity were included in the "Kids Beating Anxiety (KibA)" clinical trial and received evidence-based CBT. Diagnoses, severity of diagnoses, and further dimensional outcome variables of symptoms and functioning were assessed before (baseline), after the last treatment session (POST), and at two follow-up (FU) assessments in the child and caregiver report: 6 months (6MONTHS-FU) and >2 years (mean 4.31; SD = 1.07 years) after the last treatment session (long-term FU). Results: At POST, 61.38% showed total remission of all and any ADs. At long-term FU, the remission rate was 63.64%. Compared to baseline, ratings of severity, anxiety, impairment/burden, and life quality improved significantly after CBT in child and caregiver report. All pre-post/FU improvements and global success ratings were stable in child (Pre-Post: Hedges' g = 3.57; Pre-6MONTHS-FU: Hedges' g = 3.43; Pre-LT-FU: Hedges' g = 2.34) and caregiver report (Pre-Post: Hedges' g = 2.00; Pre-6MONTHS-FU: Hedges' g = 2.31; Pre-LT-FU: Hedges' g = 2.31) across all POST- and FU-assessment points. Some outcomes showed further significant improvement, and no deterioration was found over the course of time. Effect sizes calculated in the present study correspond to, or even exceed, effect sizes reported in previous meta-analysis. Conclusions: Stable long-term effects of "KibA" CBT for youth with ADs, comparable to those results from efficacy studies, were achieved in a routine practice setting by applying treatment manuals tested in randomized controlled trials. These findings are remarkable, as the patient group studied here consisted of an age group within the main risk phase of developing further mental disorders, and therefore an increase in new-onset anxiety and further mental disorders would be expected over the long time span studied here.