The onset of bipolar disorder typically occurs in late adolescence or early adulthood. This time is widely recognised as an important developmental stage associated with tasks including individuation from the family, consolidation of identity, moving out of home, gaining financial independence, finding employment or engaging in study, and the development of sexual and peer relationships. Therefore it is crucial that clinicians working with young people maintain a strong awareness of the profound impact that bipolar disorder can have on a person's developmental trajectory and also how developmental issues may affect an individual's presentation and engagement in treatment. This poster will provide data on developmental characteristics and issues relevant to a cohort of young people treated for first episode mania at the Early Psychosis Prevention and Intervention Centre in Melbourne. The implications of these characteristics for treatment will be discussed. We believe that existing psychological treatments for bipolar disorder require significant modification, and specifically that greater attention should be paid to developmental issues, to make these interventions applicable to young individuals who are in the early stages of the illness.