Disruptive Mood Dysregulation Disorder (DMDD) is a new diagnosis in DSM V. It was added as a diagnosis to fill a gap in important diagnostic categorization when thinking about childhood psychiatric concerns. While there is overlap in symptoms among DMDD and Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD) and Bipolar Disorder, there are important differences as well. Children with DMDD present with severe and recurrent temper outbursts that are grossly out of proportion in intensity or duration to the situation and occur several times per week. The temper outbursts have to be disproportionate to the child’s developmental age and can include verbal and physical aggression. Between these temper outbursts, children with DMDD display a persistently irritable or angry mood, most of the day, nearly everyday that is observable by others in at least two different settings for at least 12 months. This is important to rule out situational or relationship-based irritability. The persistent irritability is really the hallmark of this disorder. The onset of symptoms must be before age 10 but not younger than 6. It is thought that DMDD is more likely to occur in boys than girls. The prevalence is not yet known, but is expected to be in the 2-5% range.
ADHD is a neurodevelopmental disorder characterized by impairing hyperactivity, impulsivity and inattention, and persistent irritability and out of proportion temper outbursts are not typically seen with ADHD alone. Children with DMDD can have some challenges with hyperactivity and impulsivity but with the underlying irritability and angry mood present as well. A child can present with both diagnoses concurrently.
Children with ODD exhibit a pattern of anger-guided disobedience and defiant behavior toward authority figures. Clinically it is observed that ODD stems from learned behavior and/or parenting challenges, whereas DMDD seems to have a more organic process. While some of the symptoms of ODD may overlap with the criteria for DMDD, the symptom threshold for DMDD is higher since it is considered to be a more severe condition. Most children with DMDD also meet criteria for ODD and about 15% of children with ODD also meet criteria for DMDD. Therefore it is recommended that children who meet the criteria for both ODD and DMDD should only be diagnosed with DMDD.
Children with bipolar disorder can have symptoms that are similar to those with DMDD. The primary difference is that the mood symptoms seen in bipolar disorder are episodic, which is not the case in DMDD. If the irritability is episodic and there are also distinct periods of depression, a child is more likely to have bipolar disorder. A diagnosis of pediatric bipolar disorder would rule out DMDD. It has been shown that children who present with chronic, rather than episodic, irritability, who may have been given a diagnosis of bipolar disorder for lack of a better fit, are at greater risk of developing depression and generalized anxiety rather than life-long bipolar disorder. This was additional information to support the idea that a different diagnosis was needed to describe children with clinically impairing chronic irritability.
Because DMDD is such a new diagnosis, research is being conducted to determine the is being conducted to determine the best treatment. Medication, including SSRIs and stimulants, psychotherapy and a combination of the two are being used. The differential diagnosis includes: ADHD, ODD, bipolar disorder, major depression, substance abuse and ASD. It is important to assess for co-morbid symptoms, underlying factors and antecedents/triggers to help make an accurate diagnosis.