A systematic review of predictors and moderators of improvement in cognitive-behavioral therapy for panic disorder and agoraphobia

Abstract

Background: Despite the considerable efficacy of cognitive-behavioral therapy (CBT) for panic disorder (PD) and agoraphobia, a substantial minority of patients fail to improve for reasons that are poorly understood.Objective: The aim of this study was to identify consistent predictors and moderators of improvement in CBT for PD and agoraphobia.Data sources: A systematic review and meta-analysis of articles was conducted using PsycInfo and PubMed. Search terms included panic, agoraphobi*, cognitive behavio*, CBT, cognitive therapy, behavio* therapy, CT, BT, exposure, and cognitive restructuring.Study selection: Studies were limited to those employing semi-structured diagnostic interviews and examining change on panic- or agoraphobia-specific measures.Data extraction: The first author extracted data on study characteristics, prediction analyses, effect sizes, and indicators of study quality. Interrater reliability was confirmed.Synthesis: 52 papers met inclusion criteria. Agoraphobic avoidance was the most consistent predictor of decreased improvement, followed by low expectancy for change, high levels of functional impairment, and Cluster C personality pathology. Other variables were consistently unrelated to improvement in CBT, understudied, or inconsistently related to improvement.Limitations: Many studies were underpowered and failed to report effect sizes. Tests of moderation were rare.Conclusions: Apart from agoraphobic avoidance, few variables consistently predict improvement in CBT for PD and/or agoraphobia across studies.