If you're trying to fight fire, should you use fire?
This, pretty much, is the question asked by a group of psychiatrists in a new paper: Will disruptive mood dysregulation disorder (DMDD) reduce false diagnosis of bipolar disorder in children?
The background here is that there's growing concern that bipolar disorder, previously thought to be extremely rare in prepubescent children, is now being diagnosed, inappropriately, in children - specifically in American children. This epidemic of so-called "pediatric bipolar disorder" (PBD) shows no signs of abating.
In response to these concerns, the proposed new fifth edition of the Diagnostic and Statistical Manual (DSM-5) is slated to introduce a new disorder - DMDD. The stated purpose of DMDD is to prevent children getting a diagnosis of PBD - but only by giving them another diagnosis instead.
As I said in 2010 (note, TDDD is the old name of DMDD)
We can all sympathize with the sentiment behind TDDD - but this is fighting fire with fire. Is the only way to stop kids getting one diagnosis, to give them another one? ... Can't we just decide to diagnose people less? Apparently, that would be a rather too radical change...
Now, according to the authors of the new paper, if DMDD becomes an official diagnosis, it would only slightly reduce the number of PBD diagnoses - and
If indeed DMDD is a true entity, we suspect that, like bipolar disorder, it, too, will be overdiagnosed.
This was based on a study of 82 kids who were admitted to a specialist children's psychiatric hospital. Of the children, 30% met DMDD criteria based on parental report - but only half of those diagnoses were confirmed by observation of the child'd behaviour in hospital. Parents, in other words, over-rated DMDD symptoms. A rigorous DMDD diagnosis would only "save" a minority of children from a PBD diagnosis.
Even in those cases where "DMDD" seems most justified, it's really not clear who would benefit from giving them another diagnosis because they always qualified for 3 or more other diagnoses. Take a look at this table, showing the frankly ridiculous array of "different" disorders diagnosed in 12 children - the ones who were rated most likely to be "bipolar" by parental report -
Many parents reported "bipolar" symptoms but only 2 of 12 were judged to be actually bipolar; those two incidentally were aged 11 and 12 - consistent with the old view that bipolar is very rare before puberty.
So even if DMDD is a marginally better diagnosis than PBD - do we really need to give out any more diagnoses to kids like this?
The funny thing is that overdiagnosis of PBD is just about the only concern that the DSM-V committee is responding to at all. There are plenty of other well-publicized concerns: overdiagnosis of ADHD, overdiagnosis of depression... most of these are about overdiagnosis to be honest. Anyway, in those cases, DSM-V is proposing to either do nothing much, or actually expand the diagnostic criteria.
For PBD, they are at least trying, so perhaps they deserve some points for effort.
Margulies DM, Weintraub S, Basile J, Grover PJ, and Carlson GA (2012). Will disruptive mood dysregulation disorder reduce false diagnosis of bipolar disorder in children? Bipolar disorders, 14 (5), 488-96 PMID: 22713098