There is a need to assess the contribution of mood disorder, especially anxiety and depression, in order to understand the experience of suffering in the setting of medical practice. Most physicians are aware of this aspect of the illness of their patients but many feel incompetent to provide the patient with reliable information. The Hospital Anxiety And Depression Scale, or HADS, was designed to provide a simple yet reliable tool for use in medical practice. The term 'hospital' in its title suggests that it is only valid in such a setting but many studies conducted throughout the world have confirmed that it is valid when used in community settings and primary care medical practice. It should be emphasised that self-assessment scales are only valid for screening purposes; definitive diagnosis must rest on the process of clinical examination.