Disruptive mood dysregulation disorder (DMDD)—a childhood condition of extreme irritability, anger, and frequent, intense temper outbursts—has been a source of controversy among clinicians in the field of pediatric mental health. Before DSM-5 was published, the validity of DMDD had been questioned because DMDD had failed a field trial; agreement between clinicians on the diagnosis of DMDD was poor.1 Axelson2 and Birmaher et al3 examined its validity in their COBY (Course and Outcome of Bipolar Youth) sample. They concluded that only 19% met the criteria for DMDD in 3 times of follow-up. Furthermore, most DMDD criteria overlap with those of other common pediatric psychiatric disorders, including oppositional defiant disorder (ODD), attention-deficit/hyperactivity disorder (ADHD), and pediatric bipolar disorder (BD). Because diagnosis of pediatric BD increased drastically from 2.9% to 15.1% between 1990 and 2000,4 it was believed that introducing DMDD as a diagnosis might lessen the overdiagnosis of pediatric BD by identifying children with chronic irritability and temper tantrums who previously would have been diagnosed with BD.
It is important to recognize that in pediatric patients, mood disorders present differently than they do in adults.5 In children/adolescents, mood disorders are less likely to present as distinct episodes (narrow band), but more likely to present as chronic, broad symptoms. Also, irritability is a common presentation in many pediatric psychiatric disorders, such as ODD, BD (irritability without elation),6 and depression. Thus, for many clinicians, determining the correct mood disorder diagnosis in pediatric patients can be challenging.
This article describes the diagnosis of DMDD, and how its presentation is similar to—and different from—those of other common pediatric psychiatric disorders.
The origin of DMDD
Many researchers have investigated the broadband phenotypical presentation of pediatric mood disorders, which have been mostly diagnosed in the psychiatric community as pediatric BD. Leibenluft7 identified a subtype of mood disorder that they termed “severe mood dysregulation” (SMD). Compared with the narrow-band, clearly episodic BD, SMD has a different trajectory, outcome, and findings on brain imaging. SMD is characterized by chronic irritability with abnormal mood (anger or sadness) at least half of the day on most days, with 3 hyperarousal symptoms, including pressured speech, racing thoughts or flight of ideas, intrusiveness, distractibility, insomnia, and agitation.8 Eventually, SMD became the foundation of the development of DMDD.
DSM-5 diagnostic criteria for DMDD include severe recurrent temper outbursts that are out of proportion to the situation, inconsistent with developmental level, and occurring on average ≥3 times per week, plus persistently irritable or angry mood for most of the day nearly every day.9 Additional criteria include the presence of symptoms for at least 12 months (without a symptom-free period of at least 3 consecutive months) in ≥2 settings (at home, at school, or with peers) with onset before age 10. The course of DMDD typically is chronic with accompanying severe temperament. The estimated 6-month to 1-year prevalence is 2% to 5%; the diagnosis is more common among males and school-age children than it is in females and adolescents.9,10
DMDD or bipolar disorder?
A patient cannot be dually diagnosed with both disorders. If a patient exhibits a manic episode for more than 1 day, that would null and void the DMDD diagnosis. However, in a study to evaluate BD in pediatric patients, researchers divided BD symptoms into BD-specific categories (elevated mood, grandiosity, and increased goal-directed activity) and nonspecific symptoms such as irritability and talkativeness, distractibility, and flight of ideas or racing thoughts. They found that in the absence of specific symptoms, a diagnosis of BD is unlikely to be the correct diagnosis.11 Hence, as a nonspecific symptom, chronic irritability should be attributed to the symptom count for DMDD, rather than BD. Most epidemiologic studies have concluded that depression and anxiety, and not irritability, are typically the preceeding presentations prior to the development of BD in young adults.12 Chronic irritability, however, predicts major depressive disorder and anxiety disorders in later adolescence and one’s early twenties.13 Furthermore, BD commonly presents with infrequent and discrete episodes and a later age of onset, while DMDD presents with chronic and frequent, severe temper outbursts. Some differences between DMDD and BD are illustrated in Table 1.11-13
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