Friday, May 31, 2013

A Child Psychiatrist's Thoughts on DSM-5: Disruptive Mood Dysregulation Disorder

This is part 6 of my series on the DSM-5. Previous posts covered general impressions, PTSD, ADHD, autism, and bipolar.

One of the most controversial additions to DSM-5 has to be disruptive mood dysregulation disorder (DMDD), née temper dysregulation disorder with dysphoria (TDDD). The name was supposedly changed because some objected to the negative connotations of saying a child has a temper disorder. This diagnosis tries to answer the question: "So what do we call children who display chronic irritability and have severe tantrums, but do not really have the classic manic or hypomanic symptoms of bipolar disorder?"

The DMDD diagnosis largely grew out of research by Ellen Leibenluft at the NIMH. Her studies examining "broad phenotype" bipolar disorder (the kind of BD advanced by Wozniak, Biederman, et al, which Leibenluft prefers to call "severe mood dysregulation", or SMD) showed that children with this condition were more likely to be diagnosed with depression as young adults, but did not appear at elevated risk of developing actual manic episodes. JAACAP just published a very good review article in May that summarizes the differences between SMD and bipolar.

The DSM-5 mood disorders work group took SMD and modified it to become DMDD. The two are largely similar, with the main difference being that DMDD does not require hyperarousal symptoms such as insomnia, racing thoughts, or intrusiveness. One can certainly argue that there's less evidence to support SMD/DMDD as a distinct entity than there is for other conditions (such as melancholia) which did not end up in the DSM-5 as a separate disorder. Obviously, the DSM is based on an expert consensus process, which reflects politics and cultural trends, not just science. This is neither good nor bad, but just the way the DSM has always been.

Most online reports about DMDD that I have seen have been wrong or misleading (example 1, example 2) because they tend to focus on the mistaken notion that DMDD is just about temper tantrums. The actual diagnostic criteria include: 1) Severe recurrent temper tantrums, inconsistent with developmental level, that are out of proportion to the situation, occurring 3+ times per week; 2) Mood between tantrums is angry or irritable for most of the day, almost every day; 3) Symptoms have lasted more than a year; 4) Must be present in at least 2 settings (school, home, peers).

The symptoms must have an onset by the age of 10, so that the irritable mood of adolescence does not become a confounding factor, and the diagnosis cannot be made for the first time before age 6 or after age 18. The diagnosis also supersedes oppositional defiant disorder (ODD), and can be viewed as a more severe form of ODD. These are pretty stringent criteria, designed specifically to capture severe impairment. In Dr. Leibenluft's SMD population, around 38% of those children have had at least one psychiatric hospitalization. In the past year, I have seen 2, maybe 3 children who would meet the criteria for DMDD.

At last year's American Academy of Child and Adolescent Psychiatry meeting, Dr. Leibenluft, when asked about the new DSM-5 diagnosis, said "I'm about 65% pro-DMDD." I think that's as good an illustration as any that there's very little certainty in psychiatry, and there are pros and cons to the creation of any new diagnosis.

In this case, I think it's good that there is an alternative to labeling irritable, tantrum-prone children as having bipolar. Currently, like ODD, there are no medications for DMDD, so the focus should be on psychotherapeutic and family interventions. On the other hand, I'm sure many folks will end up ignoring the diagnostic criteria altogether and call any tantrum-prone child "DMDD." Also, I'd be surprised if Abilify does not become FDA-approved for treating DMDD by 2016.

Update (4/15/15): I've written a new post with my current thoughts on DMDD, including a review of recent research. You can read it here.