She said an expansion of the mixed states definition is on the docket for the next edition of the DSM, to which she is a contributor.
"I think this is one of the main reasons why we miss folks with bipolar disease on evaluation at presentation," she said.
The full mixed episode category affects about a third of patients with bipolar disorder, predominantly women. A study in the Journal of the American Medical Association in 1994 reported that 38% of patients hospitalized with acute mania had mixed or dysphoric mania.
Dr. Suppes said it is even more common for patients further along in the course of the disorder -- 10 to 15 years -- who continue to cycle.