Predictors and moderators of treatment dropout in cognitive-behavioral and psychodynamic therapies for panic disorder

Introduction: Panic disorder patients who drop out of treatment typically do not remit from their disorder. How patient-level moderators influence dropping out of one panic-focused treatment over another has never been examined, nor in non-CBT treatments. Method: 200 patients with panic disorder with or without agoraphobia were randomized to receive cognitive- behavioral therapy (CBT), panic-focused psychodynamic psychotherapy (PFPP), or applied relaxation training (ART) across two sites. Therapy was twice a week for 12 weeks. A two-step variable search method was applied to identify potential prognostic predictors and moderators of patient dropout. Survival models predicting hazard of session-by-session dropout tested the resulting variables. Results: Across treatments, unemployment and higher psychosocial disability on the Sheehan Disability Scale predicted increased risk of dropout, while patients with higher anxiety sensitivity were more likely to complete treatment. Patients who reported experiencing childhood abuse had heightened dropout in ART, but not CBT or PFPP. Men were especially likely to complete PFPP. Session 2 expectancies and patient-rated alliance predicted lower dropout only in CBT. Conclusions: Patient-level factors may influence both whether patients will complete any treatment, and whether they continue in a particular panic-focused therapy. Moderators of dropout (e.g., abuse history) may inform treatment decisions for specific patients.