A substantial percentage of cancer patients suffers from psychosocial distress to severe mental disorders and psychosocial crisis during the course of the illness and cancer treatment. However, only a small percentage of patients with severe psychosocial distress and mental disorders in the present oncological practice is accurately identified, diagnosed, and appropriately treated. Therefore, sufficient knowledge about psychosocial distress and mental disorders as well as screening procedures are urgent concerns to improve psychosocial care for cancer patients. First, the article provides an overview of psychosocial distress and the epidemiology of mental disorders in cancer patients. Then a few of the most important objectives and problems of psychosocial assessment in cancer patients will be explained. The following part will offer an overview of questionnaires and screening procedures that are frequently used to assess psychosocial distress, mental disorders, personal and social resources, and health related quality of life in cancer patients.
