The diagnosis of bipolar affective disorder (BD) is often delayed, and preceded by incorrect diagnoses and potentially harmful treatment, while the development of the disorder is associated with suicidal behavior and help seeking. Several clinical features have been linked to an increased risk of going on to develop BD, in particular attenuated symptoms of BD, personality traits such as cyclothymia, and general psychopathologic symptoms. Several of these show high specificity, indicating that it may be possible to target detection and intervention in individuals at high risk of BD and perhaps moderate the course of the illness and improve treatment outcome. This article summarizes recent evidence on the characteristics of the prodrome to BD and discusses the potential value and challenges of early detection and intervention in BD.