This article is from the Bipolar Disorder FAQ, by firstname.lastname@example.org (Barry Campbell) with numerous contributions by others.
Criteria for Mixed Episode (DSM-IV, p. 335)
A. The criteria are met both for a Manic Episode and for a Major Depressive
Episode (except for duration) nearly every day during at least a 1-week
B. The mood disturbance is sufficiently severe to cause marked impairment in
occupational functioning or in usual social activities or relationships with
others, or to necessitate hospitalization to prevent harm to self or others,
or there are psychotic features.
C. The symptoms are not due to the direct physiological effects of a substance
(e.g., a drug of abuse, a medication, or other treatment) or a general medical
condition (e.g., hyperthyroidism).
Comment: This may be an instance in which the DSM-IV definition is a
bit too narrow. Many readers and participants in ASDM and SSDM report
experiencing mixed states with hypomanic, but not fully manic, features.