Disruptive mood dysregulation disorder

Signs and symptoms

Most parents of children with DMDD report that their children first showed signs and symptoms of the disorder during their preschool years. Children with DMDD show severe and recurrent temper outbursts three or more times per week. Although many children have occasional tantrums, youths with DMDD have outbursts that are out of proportion in terms of their intensity or duration. These outbursts can be verbal or behavioral. Verbal outbursts often are described by observers as "rages" or "fits". Children may scream, yell, and cry for excessively long periods of time, sometimes with little provocation. Physical outbursts may be directed toward people or property. Children may throw objects; hit, slap, or bite others; destroy toys or furniture; or otherwise act in a harmful or destructive manner.

Children with DMDD also display persistently irritable or angry mood that is observable by others. Parents, teachers, and classmates describe these children as habitually angry, touchy, grouchy, or easily "set off". Unlike the irritability that can be a symptom of other childhood disorders, such as ODD, anxiety disorders, and major depressive disorder, 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.

The DSM-5 includes several additional diagnostic criteria which describe the duration, setting, and onset of the disorder: the 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 ten, and diagnosis must be made between ages 6 and 18. This new diagnosis was implemented to help children who, although may have been diagnosed with bipolar disorder, their explosive rages were not being treated properly.

Causes

The causes of DMDD are poorly understood.

Youth with DMDD have difficulty attending, processing, and responding to negative emotional stimuli and social experiences in their everyday lives. 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. Functional MRI studies suggest that under-activity of the amygdala, the brain area that plays a role in the interpretation and expression of emotions, is associated with these deficits. Deficits in interpreting social cues may predispose children to instances of anger and aggression in social settings with little provocation. For examples, youths with DMDD may selectively attend to negative social cues (e.g., others scowling, teasing) and minimize all other information about the social events. They may also misinterpret the emotional displays of others, believing others' benign actions to be hostile or threatening. Consequently, they may be more likely than their peers to act in impulsive and angry ways.

Children with DMDD may also have difficulty regulating negative emotions once they are elicited. To study these problems with emotion regulation, researchers asked children with DMDD to play computer games that are rigged so that children will lose. While playing these games, children with DMDD report more agitation and negative emotional arousal than their typically-developing peers. Furthermore, youths with DMDD showed markedly greater activity in the medial frontal gyrus and anterior cingulate cortex, than comparison 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 findings suggest that youths with DMDD are more strongly influenced by negative events than other youths. They may become more upset and select less effective and socially acceptable ways to deal with negative emotions when they arise. Last, DMDD at the age of 6 years predicted greater functional impairment, peer problems and educational support service use at the age of 9 years, after controlling for all psychiatric disorders at the age of 6 years.

Comorbidity

The core features of DMDD—temper outbursts and chronic irritability—are sometimes seen in children and adolescents with other psychiatric conditions. Differentiating DMDD from these other conditions can be difficult. Three disorders that most closely resemble DMDD are attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and bipolar disorder in children. Additionally, in both community and clinical samples DMDD is highly comorbid with internalizing and externalizing disorders, particularly with ODD, and long-term functional outcome is likely poor.

ADHD

ADHD is a neurodevelopmental disorder characterized by problems with inattention and/or hyperactivity-impulsivity.

Children with DMDD often show several features of hyperactivity and impulsiveness characteristic of ADHD. However, DMDD can be differentiated from ADHD in at least two ways. First, DMDD is a depressive disorder with severe mood components whereas ADHD is a neurodevelopmental disorder. A salient feature of DMDD is persistently irritable or angry mood. In contrast, children with ADHD do not typically display irritability or anger. Second, DMDD is characterized by severe, recurrent temper outbursts that are not characteristic of ADHD. Although many children with ADHD act impulsively, they typically do not show verbal or physical aggression toward other people or property. Children with ADHD can be diagnosed with DMDD.

ODD

ODD is a disruptive behavior disorder characterized by oppositional, defiant, and sometimes hostile actions directed at other people.

Like DMDD, ODD emerges in childhood and is often characterized by both irritable mood and angry outbursts. Furthermore, the features of ODD and DMDD are both persistent; children with these disorders usually experience signs and symptoms for months or years. Features of ODD and DMDD also frequently co-occur. Nearly all children with DMDD also meet diagnostic criteria for ODD. However, only about 15% of children with ODD meet diagnostic criteria for DMDD. Some experts believe DMDD is a severe form of ODD in which children's mood problems are the most salient symptom. In DSM-5, children cannot be diagnosed with both disorders. If a child meets criteria for both ODD and DMDD, only DMDD (the more serious disorder) is diagnosed.

Despite their similarity, DMDD can be differentiated from ODD in several ways. First, like ADHD, ODD is a disruptive behavior disorder not a mood disorder. Although children with ODD can show irritability and angry outbursts, their most salient feature is noncompliant and defiant behavior, such as ignoring parents, refusing to do chores, or acting in a spiteful or resentful manner. Second, children with ODD direct their oppositionality and defiance toward specific people. For example, a child with ODD may act defiantly toward his mother, but be compliant with his father. In contrast, children with DMDD direct their anger and physical aggression toward most people and also objects. For example, a child with DMDD may be tantrum with both parents, show irritability with teachers and classmates, and break objects when upset. Third, DMDD and ODD differ in the duration and severity of children's outbursts. Whereas a child with ODD may ignore parents' requests or stubbornly refuse to comply with their commands, a child with DMDD might yell, scream, or hit his parents to express anger. The outbursts of children with DMDD often appear with little provocation and last much longer than expected. Finally, children with DMDD show different developmental outcomes than youths with ODD. Whereas youths with ODD are often at risk for developing more serious conduct problems, youths with DMDD are at greater risk for anxiety and depression in later childhood and adolescence.

Bipolar disorder

One of the main differences between DMDD and bipolar disorder is that the irritability and anger outbursts associated with DMDD are not episodic; symptoms of DMDD are chronic and displayed constantly on an almost daily basis. On the other hand, bipolar disorder is characterized by distinct manic or hypomanic episodes usually lasting a few days, or a few weeks at most, that parents should be able to differentiate from their child's typical mood and behavior in between episodes. The DSM precludes a dual diagnosis of DMDD and bipolar disorder. Bipolar disorder alone should be used for youths who show classic symptoms of episodic mania or hypomania.

Prior to adolescence, DMDD is much more common than bipolar disorder. Most children with DMDD see a decrease in symptoms as they enter adulthood, whereas individuals with bipolar disorder typically display symptoms for the first time as teenagers and young adults. Children with DMDD are more at risk for developing major depressive disorder or generalized anxiety disorder when they're older rather than bipolar disorder.

Medication

Evidence for treatment is weak, and treatment is determined based on the physician's response to the symptoms that people with DMDD present. Because the mood stabilizing medication, lithium, is effective in treating adults with bipolar disorder, some physicians have used it to treat DMDD although it has not been shown to be better than placebo in alleviating the signs and symptoms of DMDD. DMDD is treated with a combination of medications that target the child's symptom presentation. For youths with DMDD alone, antidepressant medication is sometimes used to treat underlying problems with irritability or sadness. For youths with unusually strong temper outbursts, an atypical antipsychotic medication, such as risperidone, may be warranted. Both medications, however, are associated with significant side effects in children. Finally, for children with both DMDD and ADHD, stimulant medication is sometimes used to reduce symptoms of impulsivity.

Psychosocial

Several cognitive-behavioral interventions have been developed to help youths with chronic irritability and temper outbursts. Because many youths with DMDD show problems with ADHD and oppositional-defiant behavior, experts initially tried to treat these children using contingency management. This type of intervention involves teaching parents to reinforce children's appropriate behavior and punish (usually through systematic ignoring or time out) inappropriate behavior. Although contingency management can be helpful for ADHD and ODD symptoms, it does not seem to reduce the most salient features of DMDD, namely, irritability and anger.

Epidemiology

There are not good estimates of the prevalence of DMDD as of 2015, but primary studies have found a rate of 0.8 to 3.3%. Epidemiological studies show that approximately 3.2% of children in the community have chronic problems with irritability and temper, the essential features of DMDD. These problems are probably more common among clinic-referred youths. Parents report that approximately 30% of children hospitalized for psychiatric problems meet diagnostic criteria for DMDD; 15% meet criteria based on the observations of hospital staff.

Prognosis

Little is known about the course of DMDD. The chronic irritability and angry outbursts that characterize DMDD often last through early adolescence if left untreated, although well-designed prospective longitudinal studies are lacking. In terms of prolonged effects of DMDD and issues in adulthood, participants in a longitudinal study that exhibited a history of DMDD were more likely than their counterparts to come from impoverished families and single-parent homes. Additionally, participants with a childhood DMDD diagnosis were more likely to develop depressive or anxiety disorders as adults; had higher rates of poor health outcomes such as STD transmission, illness, and smoking; were more likely to engage in illegal or risky behaviors as well as be convicted of felony charges; and were more likely to be impoverished DMDD at the age of 6 years also predicted current and lifetime depressive disorder and attention-deficit/hyperactivity disorder (ADHD) at the age of 9 years, after controlling for all age 6 years psychiatric disorders.

History

Beginning in the 1990s, some clinicians began observing children with hyperactivity, irritability, and severe temper outbursts. These symptoms greatly interfered with their lives at home, school, and with friends. Because other diagnoses, like ADHD and ODD, did not capture the severity of children's irritability and anger, many of these children were diagnosed with bipolar disorder. Longitudinal studies showed that children with chronic irritability and temper outbursts often developed later problems with anxiety and depression and rarely developed bipolar disorder in adolescence or adulthood. Consequently, the developers of DSM-5 created a new diagnostic label, DMDD, to describe children with persistent irritability and angry outbursts. In 2013, the American Psychiatric Association (APA) added DMDD to the DSM-5 and classified it as a depressive disorder.