What is a requirement regarding age for a diagnosis of Disruptive Mood Dysregulation Disorder?

Disruptive Mood Dysregulation Disorder (DMDD) is specifically characterized by severe temper outbursts that are out of proportion to the situation, alongside a persistently irritable or angry mood. For a diagnosis of DMDD, it is a requirement that the symptoms must begin before the individual reaches the age of 10. This age criterion is critical because it aims to distinguish DMDD from other mood disorders, particularly to prevent the over-diagnosis of bipolar disorder in children. Therefore, the correct response highlights this essential feature of the disorder's diagnostic criteria in the DSM-5.

This age requirement helps to ensure that the diagnosis is appropriate for the developmental stage of the individual and reflects a pattern of behavior that is not merely situational or stress-induced but indicative of a more pervasive problem.