Single episode depressive disorder, unspecified severity

**Definition:** Single episode depressive disorder, unspecified severity is diagnosed when the definitional requirements of a depressive episode have been met, there is no history of prior depressive episodes, and there is insufficient information to determine the severity of the current depressive episode. A depressive episode is characterised by a period of depressed mood or diminished interest in activities occurring most of the day, nearly every day during a period lasting at least two weeks accompanied by other symptoms such as difficulty concentrating, feelings of worthlessness or excessive or inappropriate guilt, hopelessness, recurrent thoughts of death or suicide, changes in appetite or sleep, psychomotor agitation or retardation, and reduced energy or fatigue. The symptoms are associated with at least some difficulty in continuing with ordinary work, social, or domestic activities.