Disruptive Mood Dysregulation Disorder 157
The clinical presentation of disruptive mo od dysregulation disord er must be carefully
distinguished from presentations of other, re lated conditions, particularly pediatric bi-
polar disorder. In fact, disruptive mood dy sregulation disorder was added to DSM-5 to
address the considerable concern about the appropriate classification and treatment of
children who present with chronic, persistent irritability relative to children who present
with classic (i.e., episo dic) bipolar disorder. 
Some researchers view severe, non-episodic ir ritability as characteristic of bipolar dis-
order in children, although both DSM-IV and DSM-5 require that both children and adults
have distinct episodes of mania or hypomania to qualify for the diagnosis of bipolar I dis-
order. During the latter decades of the 20th century, this contention by researchers that
severe, nonepisodic irritability is a manifestat ion of pediatric mania coincided with an up-
surge in the rates at which clinicians assigned the diagnosis of bipolar disorder to their
pediatric patients. This sharp increase in rates appears to be attributab le to clinicians com-
bining at least two clinical presentations into a single category. That is, both classic, epi-
sodic presentations of mania and non-episodic  presentations of severe irritability have
been labeled as bipolar disorder in children. In DSM-5, the term bipolar disorder  is explicitly
reserved for episodic presentations of bipolar symptoms. DSM-IV did not include a diagno-
sis designed to capture youths whose hallmar k symptoms consisted of very severe, non-
episodic irritability, whereas DSM-5, with the inclusion of disruptive mood dysregulation
disorder, provides a distinct ca tegory for such presentations. 
Prevalence