The American Psychiatric Association is set to add "disruptive mood dysregulation disorder" to the Diagnostic Statistical Manual (DSM), the bible of psychiatric disorders. A kid has "DMDD" if she or he has "severe recurrent temper outbursts that are grossly out of proportion in intensity or duration to the situation… at least three times a week."
As Wired's David Dobbs notes, this describes basically all kids ("No, I don't want to wear my rain boots!") at some time or another. So why is this being considered? Here's Neuroskeptic's explanation:
DMDD seems to be nothing to do with mood, but instead covers a pattern of misbehavior which is already covered by not one but two labels already. Why add a misleadingly-named third?
Well, the back-story is that in the past ten years, many American kids and even toddlers have got diagnosed with 'child bipolar disorder' – a disease considered extremely rare everywhere else. To stop this, the DSM-5 committee want to introduce DMDD as a replacement. This is the officially stated reason for introducing it. On the evidence of this paper and others it wouldn't even achieve this dubious goal.
The possibility of just going to back to the days when psychiatrists didn't diagnose prepubescent children with bipolar (except in very rare cases) seems to not be on the table.