Background: A specific psychotherapy for chronic depression, the Cognitive Behavioral Analysis System of Psychotherapy (CBASP), was compared to escitalopram (ESC). Methods: Sixty patients with chronic major depression were randomized to ‘CBASP' (22 sessions) or ‘ESC plus clinical management' (ESC/CM) at two treatment sites. The primary outcome measure was the score on the Montgomery-Asberg Depression Rating Scale (MADRS) after 8 weeks of acute treatment assessed by blinded raters. In the case of nonimprovement (<20% reduction in the MADRS score), the other condition was augmented for the following 20 weeks of extended treatment. Secondary end points were, among others, depressive symptoms, remission (MADRS score of ≤9) and response rates (reduction of MADRS score of ≥50%) 28 weeks after randomization. Results: An intent-to-treat analysis revealed that clinician-rated depression scores decreased significantly after 8 and 28 weeks with no significant differences between the groups. The response rates after 28 weeks of treatment were high (CBASP: 68.4%, ESC/CM: 60.0%), and the remission rates were moderate (CBASP: 36.8%, ESC/CM: 50.0%) with neither group being superior. Nonimprovers to the initial treatment caught up with the initial improvers in terms of depression scores and response and remission rates by the end of the treatment after being augmented with the respective other condition. Conclusions: CBASP and ESC/CM appear to be equally effective treatment options for chronically depressed outpatients. For nonimprovers to the initial treatment, it is efficacious to augment with medication in the case of nonresponse to CBASP and vice versa.