The primary aim of the first study is to conduct a comparative outcome investigation of highly promising cognitive-behavioral treatments - derived from the Cognitive Model of Panic (CMP) and the Cognitive Model of Agoraphobia (CMA) for Panic Disorder with Agoraphobia (PDA). The study will compare an integrated Cognitive Therapy alone vs. Cognitive Therapy + Applied Relaxation Training vs. Cognitive Therapy + Relaxation Training + graduated in vivo exposure using tripartite assessments and long- term follow-up to determine their efficacy, generalizability, tolerability, maintenance, social and clinical significance. The mediating influence of stressful life events and individual differences will be evaluated regarding both outcome and maintenance effects. Longitudinal follow-ups will examine cognitive, behavioral, physiological functioning, psychological adjustment, relapse and the emergence of other psychiatric disorders. Seventy-two patients meeting DSM-III-R criteria for PDA will be randomly assigned to one of the three treatments. Protocol therapists, whose treatment integrity will be objectively monitored, will be counterbalanced across the treatmets. A comprehensive assessment battery will be used to pre, mid, post, 3, 6, 12 and 24-month follow-ups. The proposed study will address critical conceptual, methodological and clinical-research issues and provide important information on the effectiveness, clinical significance and long-term benefits of these promising psychosocial treatments for PDA. The second major objective of the proposal is to conduct a longitudinal follow-up of agoraphobics treated in the current NIMH protocol consisting of graduated exposure alone vs. Relaxation Training + graduated expsoure vs. Cognitive Therapy + graduated exposure (without CMP rationale or treatments). The role of individual differences, response profiles, stressful life events and marital adjustment will be examined with regard to concordance, synchrony, maintenance, relapse, need for interim treatment, booster sessions and treatment generalization across the tridimensional systems. Moreover, the clinical and social significance of th treatements on a long-term basis will be examined by comparing treated subject to normative, non-phobic cohorts. The follow-up investigation would provide valuable data regarding the long-term trajectory of these treatments and the mediating influence of stressful life events in maintenance and relapse phenomena.