Conceptualizing and treating chronic depression: A naturalistic study of psychotherapy and combination treatment

Psychotherapy and antidepressant medication (ADM) are different treatments that presumably work through different mechanisms of change, but they seem to work equally well to treat chronic depression. The nature of depression and the mechanisms through which various treatments may affect symptoms, remain largely unknown. Establishing how treatments may act differently on specific symptom groupings could assist therapists in assigning patients to treatments that better fit their needs. The overarching aim of this thesis was to explore how different treatment conditions might affect specific symptoms of chronic depression and discuss possible mechanisms underlying these effects. The results indicate patients with chronic depression may experience oppositional tolerance to ADM and not benefit from continued use, and that psychotherapy may be a viable alternative to combination treatment. Also, self-criticism may be a key factor in maintaining chronic depression, and ADM may have negative effects on psychotherapeutic interventions that target self-criticism. The results challenge the assertion that combination treatment is better than monotherapy for patients with chronic depression