who has ever experienced a full-duration hypoma nic or manic episode (irritable or euphoric)
or who has ever had a manic or hypomanic epis ode lasting more than 1 day. Another central
differentiating feature between bipolar disorder s and disruptive mood dysregulation disorder
is the presence of elevated or expansive mood and grandiosity. These symptoms are common
features of mania but are not characteristic of disruptive mood dy sregulation disorder. 
Oppositional defiant disorder. While symptoms of opposition al defiant disorder typi-
cally do occur in children with disruptive mood dysregulation disorder, mood symptoms
of disruptive mood dysregulation disorder ar e relatively rare in children with opposi-
tional defiant disorder. The key features that warrant the diagnosis of disruptive mood
dysregulation disorder in children whose sympto ms also meet criteria  for oppositional de-
fiant disorder are the presence of severe an d frequently recurrent outbursts and a persis-
tent disruption in mood betw een outbursts. In addition, the diagnosis of disruptive mood
dysregulation disorder requires severe impairment in at least one setting (i.e., home,
school, or among peers) and mild  to moderate impairment in a second setting. For this rea-
son, while most children whose symptoms meet  criteria for disrup tive mood dysregula-
tion disorder will also have a presentation that meets criteria fo r oppositional defiant
disorder, the reverse is not the case. That is, in only approximately 15% of individuals with
oppositional defiant disorder would criteria  for disruptive mood dysregulation disorder
be met. Moreover, even for child ren in whom criteria for both disorders are met, only the
diagnosis of disruptive mood dysregulation disorder should be made. Finally, both the