DMDD at the Nexus of Internalizing and Externalizing Disorders

The chapter delves into the unique diagnostic landscape of disruptive mood dysregulation disorder (DMDD) within the realm of childhood mental health. DMDD, introduced in the 2013 DSM-5, stands as the sole depressive disorder necessitating diagnosis before the age of 18. Its inception emerged from a contentious debate in the field, where questions persisted regarding the accurate diagnosis of bipolar disorder in younger children. This chapter traces the origins of DMDD from the research syndrome known as severe mood dysregulation (SMD). By exploring DMDD’s position at the crossroads of internalizing and externalizing disorders, it sheds light on its clinical significance and relevance, offering valuable insights for mental health professionals and researchers alike.