The guidelines for diagnosis and treatment of depressive disorders are practice-oriented and evidence-based recommendations for primary care of depressive patients. They were developed in the context of subproject 3.1 "Comprehensive Quality Management in Outpatient Care" within the German Research Network on Depression and Suicidality. The guidelines were developed by research groups from study centres in Freiburg, Duesseldorf and Munich and an external expert group. In addition, a close co-operation was established with the Guideline Clearing Commission of the Agency for Quality in Medicine (AQuMed) and the Drug Commission of the German Medical Profession (AkdA) and are intended as an orientational aid in terms of a "pathway of care". The guidelines particularly address physicians in primary care. The development process followed the methodological recommendations of the Association of the Scientific Medical Societies in Germany (AWMF) and the requirements of evidence-based medicine. National and international guidelines for depressive disorders as well as Cochrane reviews (CR) and quality-assessed reviews (CRD) were taken into account. The present formulation of the treatment guidelines and the evidence was agreed upon in a consensus process that included all participants.