There is a limitation of data about factors associated with treatment response in panic disorder (PD) patients at long-term follow-up period. The aim of this study was to evaluate the long-term treatment response of pharmacotherapy-resistant patients with PD after 5 years of cognitive-behavior group therapy (CBGT) and to identify factors that predict this outcome.

Sixty-four patients who completed 12 sessions of CBGT were followed for 5-year. Outcome measures were evaluated by the Clinical Global Impression (CGI) and quality of life (QoL) using WHOQOL-bref. Demographic and clinical features, stressful life events were the variables investigated as predictors of CBGT response across follow-up period.

Treatment was associated with significant reduction in symptoms severity (agoraphobia, anticipatory anxiety and panic attacks) with maintenance of gains at 5-year of follow-up (p < 0.05). Twenty-four (40%) of the sample remained in remission after 5 years, 12 (20%) relapsed during the follow-up period and 24 (40%) were non-responder to CBGT. The poor CBGT response had an important negative impact in QoL. Regression analyzes showed that comorbidity with dysthymia (p = 0.017) and stressful life events (p = 0.012) as the most important predictors to worse response.

The improvement in all evaluations suggested that brief CBGT for pharmacotherapy-resistant patients could be an alternative as next-step strategy for residual symptoms with maintenance of the gains after 5 years as assessed across follow-up period. New strategies should be tried for resistant patients, such as those with dysthymia comorbidity, and some specific tool in order to cope with adverse events.