Long-term stability of cognitive behavioral therapy effects for panic disorder with agoraphobia: a two-year follow-up study

Cognitive-behavioral therapy (CBT) aims to help patients establish new behaviors that will be maintained and adapted to the demands of new situations. The long-term outcomes are therefore crucial in testing the durability of CBT. A two-year follow-up assessment was undertaken on a subsample of n = 146 PD/AG patients from a multicenter randomized controlled trial. Treatment consisted of two variations of CBT: exposure in situ in the presence of the therapist (T+) or on their own following therapist preparation (T-). Both variations of CBT had high response rates and, overall, maintained the level of symptomatology observed at post-treatment with high levels of clinical significance. Effect sizes 24 months following treatment were somewhat lower than at the 6-month follow up. Once patients reached responder status, they generally tended to remain responders at subsequent assessments. Differences were observed for patients that obtained additional treatment during the follow-up period. Expert opinion and subjective appraisal of treatment outcome differed. No robust baseline predictors of 2-year outcome were observed. Most patients maintain clinically meaningful changes two years following treatment across multiple outcome measures. Approximately 1/3 of patients continued to experience meaningful residual problems.