Guidelines for the diagnosis and treatment of psychiatric disorders developed on the highest qualitative methodical standard cover reliable decision guidance and are an important instrument of quality improvement in health care. They have to be accessible with little effort and should be concise and clearly presented to be used in daily routine. Early integration of members of the different professions, patients and their care givers into the development process is essential for acceptance. The development process of a S3 guideline is complex and poses a difficult challenge to personal manpower and funding, which is met by the associations of the Association of Medical Societies in Germany. Further scientific discussion is necessary to find adequate solutions for problematic topics or potential distortion, such as the consequences of inadequate reporting of studies, insufficient recording and reporting of the risk of damage, unpublished data and lacking interest of sponsors in specific topics.