Disruptive mood dysregulation disorder (DMDD) is a mental disorder in children and adolescents characterized by a persistently irritable or angry mood and frequent temper outbursts that are disproportionate to the situation and significantly more severe than the typical reaction of same-aged peers. DMDD was added to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) as a type of mood disorder diagnosis for youths. The symptoms of DMDD resemble many other disorders, thus a differential includes attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), anxiety disorders, childhood bipolar disorder, intermittent explosive disorder (IED), major depressive disorder (MDD), and conduct disorder.
DMDD first appeared as a disorder in the DSM-5 in 2013 and is classified as a mood disorder. Researchers at the National Institute of Mental Health (NIMH) developed the DMDD diagnosis to more accurately diagnose youth who may have been previously diagnosed with pediatric bipolar disorder who had not experienced episodes of mania or hypomania.
Diagnosis requires meeting criteria set by the DSM-5, which includes frequent and severe temper outbursts several times a week for over a year that are observed in multiple settings. Treatments include medication to manage mood symptoms as well as individual and family therapy to address emotional regulation skills. Children with DMDD are at risk for developing depression and anxiety later in life.
Signs and symptoms Children with DMDD show severe and recurrent temper outbursts three or more times per week. These outbursts can be verbal or behavioral. Verbal outbursts are often described by observers as "rages", "fits", or "tantrums". Temper outbursts will vary between children in type, nature, and setting, so it is important to talk with parents about the nature of the outburst and their triggers. Unlike the irritability that can be a symptom of other childhood disorders such as oppositional defiant disorder (ODD), anxiety disorders, and major depressive disorder (MDD), the irritability displayed by children with DMDD is not episodic or situation-dependent. In DMDD, the irritability or anger is severe and is shown most of the day, nearly every day in multiple settings, lasting for one or more years. In other words, it is important to discern between general irritability and tantrums that can be episodic and common in pediatric patients and the easy provocation and extreme anger expressions of threatening to kill, throwing things, or attacking someone, as seen in DMDD. While all children may experience irritability and frustration, children with DMDD have difficulty controlling the level of anger and have reactions out of proportion to the situation. For instance, a child with DMDD can become extremely upset or emotional to the point of intense temper outbursts with yelling or hitting after being asked by a parent to stop playing and complete their homework. These levels of outbursts occur multiple times per week.
Furthermore, most children with DMDD display symptoms that meet the criteria of attention deficit hyperactivity disorder (ADHD), and a smaller portion of children with ADHD will display symptoms similar to DMDD. Originally, a distinctive disorder from which DMDD was derived, severe mood dysregulation disorder (SMDD), had the requirement for at least three "hyperarousal" symptoms such as pressured speech, racing thoughts, intrusive behavior, distractibility, insomnia, and agitation, but these are not included in the most recent DMDD criteria.
Comorbidity The core features of DMDD—temper outbursts and chronic irritability—are sometimes seen in children and adolescents with other psychiatric conditions. However, in children with DMDD, comorbidities with other psychiatric disorders appear to be extremely common as well as the range of disorders that can co-occur. Common comorbidities of DMDD include ADHD, major depressive disorder, anxiety disorders, conduct disorder, and substance use disorders.
Attention deficit hyperactivity disorder Attention deficit hyperactive disorder (ADHD) is a neurodevelopmental disorder characterized by problems with inattention, hyperactivity, impulsivity, or a combination of the three. ADHD is also associated with impaired executive functioning, structural and functional abnormalities in brain parts, such as frontal-striatal, with specific gene mutation. Patients with DMDD often exhibit symptoms of ADHD due to their inattention and distractibility.
Major depressive disorder Major depressive disorder (MDD) is a mood disorder characterized by daily or nearly daily symptoms of down or depressed mood for all or almost all the day. The DSM-5 requires an individual meets 5 of 9 criteria for at least the past 2 weeks that cause significant impairment in daily life and are not caused by other medical conditions or substance use. MDD often presents differently when comparing children and adults. Young children between 3 and 8 years old presenting with somatic complaints (e.g., stomach aches, dizziness), irritability, anxiety, general behavioral problems, and less of the typical sadness commonly seen in adults. Similar to ADHD, developing MDD in early adulthood was found to be linked with persistent irritability during early adolescence, which can be seen in DMDD.
Anxiety disorder Anxiety disorders are a broad category of disorders that are all generally characterized by excessive fear (emotional response to a real or perceived imminent threat) and anxiety (the anticipation of a future threat). The objects or situations that are the sources of the fear and anxiety a person experiences, which can often lead to avoidant behavior, are used to characterize the different anxiety disorders. With DMDD, the severe mood dysregulation is associated with higher rates of anxiety and depressive disorders in the future.
Conduct disorder Conduct disorder is a behavior disorder characterized by repeated, persistent patterns of behavior that violate the rights of others and disregard major societal norms and rules. While both DMDD and conduct disorder are associated with argumentative and defiant behavior, DMDD is distinctly differentiated from conduct disorder by the DSM-5. Individuals with DMDD experience severe emotional dysregulation not seen in conduct disorder. Additionally, conduct disorder is described by a distinct lack of remorse and repeated physical harm and threats of harm to people or animals. Evidence of conduct disorder during childhood is one of the criteria for an adult diagnosis of antisocial personality disorder; however, adults with a continued diagnosis of conduct disorder do not necessarily have antisocial personality disorder.
Substance use disorder Substance use disorders (SUD) encompass a broad range of specific diagnoses, but they all generally have the characteristics of cognitive, behavioral, and physiological symptoms that cause someone to continue to use a substance despite significant impairment. One salient feature of SUDs is that they change the brain circuitry in such a way that the changes can persist beyond detoxification. In general, though, examining the comorbidity of SUDs in DMDD is important as it may be linked to self-medication for underlying mood disorders or trauma. However, while there are reports in community and clinical samples of comorbidity for SUDs with DMDD, there has been no formal examination of this link.
Pathophysiology
While no specific study has been done on children with DMDD, an NIMH research group led by Ellen Leibenluft has conducted studies on children with episodic and non-episodic irritability with neuroimaging. More specifically, these studies have used behavioral, neurocognitive, and physiologic measures that include functional magnetic resonance imaging (fMRI), event-related potentials (ERPs), and magnetoencephalography. In general, studies have shown that there are four major dysregulated domains that cause dysfunction, primarily in distress levels with frustrating tasks and emotional labeling. The specific domains include impaired emotional and attention regulation, misinterpretation of stimuli, impaired sensitivity to social context, and dysfunction of the reward system. For example, some studies have shown youths with DMDD to have problems interpreting the social cues and emotional expressions of others. These youths may be especially bad at judging others' negative emotional displays, such as feelings of sadness, fearfulness, and anger.
Compared to children with bipolar disorder and ADHD, fMRI studies suggest that under-activity of the amygdala, the brain area that plays a role in the interpretation and expression of emotions and novel stimuli, is associated with the dysregulation seen in DMDD. Other studies using fMRI have also shown that children with DMDD had deficits in bottom-up early attentional processes and deficits in activation of the brain regions associated with spatial attention, reward processing, and emotional regulation. The hypoactivity of the amygdala and the early attention process deficits mirror those found in depression and ADHD, respectively, partially explaining the comorbidity with these disorders. Furthermore, youths with DMDD showed markedly greater activity in the medial frontal gyrus and anterior cingulate cortex compared to other youths. These brain regions are important because they are involved in evaluating and processing negative emotions, monitoring one's own emotional state, and selecting an effective response when upset, angry, or frustrated. Altogether, these neural differences likely contribute to the longer recovery from frustration seen in children with DMDD, causing impairment with emotional regulation, peer relationships, identifying negative emotions, and experiencing greater fear when looking at neutral faces.
Diagnosis
DSM-5 diagnostic criteria The DSM-5 includes several additional diagnostic criteria which describe the duration, setting, and onset of the disorder that must be met to make a diagnosis. Of note, the patient's outbursts must be present for at least 12 months and occur in at least two settings (e.g. home and school), and it must be severe in at least one setting. Symptoms appear before the age of 10, and diagnosis must be made between ages 6 and 18. A summary of the criteria is as follows: