Guest Post by Brenda Patoine
Ever witnessed an all-out temper tantrum from a nap-deprived three-year-old? Now imagine living with that kind of emotional outburst day in and day out for years. This is what it’s like for parents of children with disruptive mood dysregulation disorder (DMDD), a newly recognized psychiatric syndrome that typically begins before age ten.
DMDD is among the “new” mental health disorders described in the latest edition of the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM-5), used by mental health professionals to diagnose and treat mental illness.
The kind of severe irritability and chronic crankiness that characterizes DMDD was previously thought to be a childhood manifestation of bipolar disorder, explains Ellen Leibenluft, M.D., chief of the Section on Bipolar Spectrum Disorders at the National Institute of Mental Health (NIMH). The idea was very popular among both researchers and clinicians in child psychiatry at the beginning of the century, she says, yet nobody had really tested it to see if it was true.
In an effort to sort it out, Leibenluft’s research group and others tapped into a number of existing data sets to scientifically track the progression from chronic irritability in childhood to bipolar disorder in adulthood. Their findings turned the conventional wisdom on its head.
“Children who are very irritable don’t grow up to have bipolar disorder,” Leibenluft says. “They are not at particularly high risk for bipolar. Rather, they are at high risk for unipolar depression (major depression), and anxiety disorders.”
Since that game-changing finding, a number of studies have begun to better characterize the symptoms and the underlying neurobiology in an attempt to inform treatment. Neurobiologically, children with DMDD tend to have impairments in cognitive control. In particular, they have difficulty learning a new behavior, even when they are rewarded for doing so. A number of studies have also found impairments in the children’s ability to respond appropriately to faces. They have trouble labeling facial expressions, and make significantly more mistakes than other kids do when naming an emotion they see in a picture of a face. Their attention is drawn to threatening faces, and they tend to view emotionally ambiguous faces as more negative than healthy kids do.
“It’s as if they are on guard for a threat,” Leibenluft says. “They have a bias to pay attention to threatening faces and also a bias to interpret ambiguous faces as hostile.”
While research to understand the neurobiology and behavioral patterns of DMDD progresses, studies are also underway to identify the best therapeutic approaches. Leibenluft’s group at the NIMH is spearheading a randomized, controlled clinical trial of a type of psychological therapy called Interpretation Bias Training, and is also evaluating Cognitive Behavioral Therapy for DMDD. Drug treatment may be warranted if psychological therapy is insufficient, but there is so far little empirical data to guide the use of medication in this condition.
DMDD was the subject of a NIMH Twitter Chat with Leibenluft on May 5, a day designated as Children’s Mental Health Awareness Day. The transcript of the chat is available online.