Long-term Outcomes of Cognitive Behavioral Therapy for Anxiety-Related Disorders : A Systematic Review and Meta-analysis

Question  What is the long-term outcome of cognitive behavioral therapy for anxiety disorders, posttraumatic stress disorder, and obsessive-compulsive disorder?

Findings  In this systematic review and meta-analysis of 69 randomized clinical trials including 4118 patients, cognitive behavioral therapy was associated with better outcomes compared with control conditions among patients with anxiety symptoms within 12 months after treatment completion. At longer follow-up, significant associations were found only for generalized anxiety disorder, social anxiety disorder, and posttraumatic stress disorder; relapse rates (predominantly for panic disorder with or without agoraphobia) after 3 to 12 months were 0% to 14%.

Meaning  The findings suggest that compared with control conditions, cognitive behavioral therapy was generally associated with lower anxiety symptoms within 12 months after treatment completion, but few studies have examined longer-term outcomes.

Abstract

Importance  Cognitive behavioral therapy is recommended for anxiety-related disorders, but evidence for its long-term outcome is limited.

Objective  This systematic review and meta-analysis aimed to assess the long-term outcomes after cognitive behavioral therapy (compared with care as usual, relaxation, psychoeducation, pill placebo, supportive therapy, or waiting list) for anxiety disorders, posttraumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD).

Data Sources  English-language publications were identified from PubMed, PsycINFO, Embase, Cochrane, OpenGrey (1980 to January 2019), and recent reviews. The search strategy included a combination of terms associated with anxiety disorders (eg, panic or phobi*) and study design (eg, clinical trial or randomized controlled trial).

Study Selection  Randomized clinical trials on posttreatment and at least 1-month follow-up effects of cognitive behavioral therapy compared with control conditions among adults with generalized anxiety disorder, panic disorder with or without agoraphobia, social anxiety disorder, specific phobia, PTSD, or OCD.

Data Extraction and Synthesis  Researchers independently screened records, extracted statistics, and assessed study quality. Data were pooled using a random-effects model.

Main Outcomes and Measures  Hedges g was calculated for anxiety symptoms immediately after treatment and at 1 to 6 months, 6 to 12 months, and 12 months or more after treatment completion.

Results  Of 69 randomized clinical trials (4118 outpatients) that were mainly of low quality, cognitive behavioral therapy compared with control conditions was associated with improved outcomes after treatment completion and at 1 to 6 months and at 6 to 12 months of follow-up for a generalized anxiety disorder (Hedges g, 0.07-0.40), panic disorder with or without agoraphobia (Hedges g, 0.22-0.35), social anxiety disorder (Hedges g, 0.34-0.60), specific phobia (Hedges g, 0.49-0.72), PTSD (Hedges g, 0.59-0.72), and OCD (Hedges g, 0.70-0.85). At a follow-up of 12 months or more, these associations were still significant for generalized anxiety disorder (Hedges g, 0.22; number of studies [k] = 10), social anxiety disorder (Hedges g, 0.42; k = 3), and PTSD (Hedges g, 0.84; k = 5), but not for panic disorder with or without agoraphobia (k = 5) and could not be calculated for specific phobia (k = 1) and OCD (k = 0). Relapse rates after 3 to 12 months were 0% to 14% but were reported in only 6 randomized clinical trials (predominantly for panic disorder with or without agoraphobia).

Conclusions and Relevance  The findings of this meta-analysis suggest that cognitive behavioral therapy for anxiety-related disorders is associated with improved outcomes compared with control conditions until 12 months after treatment completion. At a follow-up of 12 months or more, effects were small to medium for generalized anxiety disorder and social anxiety disorder, large for PTSD, and not significant or not available for other disorders. High-quality randomized clinical trials with 12 months or more of follow-up and reported relapse rates are needed.