A mixed affective state, formerly known as a mixed-manic or mixed episode, has been defined as a state wherein features unique to both depression and mania—such as despair, fatigue, morbid or suicidal ideation, racing thoughts, pressure of activity, and heightened irritability—occur either simultaneously or in very short succession. Previously, the diagnostic criteria for both a manic and depressive episode had to be met in a consistent and sustained fashion, with symptoms enduring for at least a week, thereby restricting the official acknowledgement of mixed affective states to only a minority of patients with bipolar I disorder. In current DSM-5 nomenclature, however, a "mixed episode" no longer stands as an episode of illness unto itself; rather, the symptomology specifier "with mixed features" can be applied to any major affective episode, meaning that they are now officially recognized in patients with, in addition to bipolar I disorder, bipolar II disorder and, by convention, major depressive disorder. A depressivemixed state in a patient, however, even in the absence of discrete periods of mania or hypomania, effectively rules out unipolar depression. Although convention dictates diagnosing such patients with major depressive disorder, it is more appropriate to classify such a patient as having an "Other Specified Bipolar or Related Disorder" and following up such patients in the long-term, to ascertain the eventual appearance of an episode of mania or hypomania, which would prompt diagnostic revision. As of now the diagnosis is only made as depression initially and later modified to agitated depression. In those uncommon cases wherein the diagnostic criteria for both a manic and depressive episode are met, constituting what were heretofore classified as "mixed episodes", such a patient would be diagnosed as having a "manic episode with mixed features", because of the substantial social and occupational dysfunction inherent in such a state.
Diagnostic criteria
As affirmed by the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, the symptomology specifier "with mixed features" can be applied to manic episodes of bipolar I disorder, hypomanic episodes of either bipolar I disorder or bipolar II disorder, and depressive episodes of either bipolar disorder or major depressive disorder, with at least three concurrent features of the opposite polarity being present. As a result, the presence of "mixed features" are now recognized in patients with bipolar II disorder and major depression; as earlier noted, however, although it is customary to withhold a diagnosis of a bipolar disorder until a manic or hypomanic episodeappears, the presence of such features in a depressed patient even with no history of discrete mania or hypomania is strongly suggestive of the disorder. Two features of both mania or hypomania and depression may superficially overlap and even resemble each other, namely "an increase in goal-directed activity" vs. psychomotor agitation and "flight of ideas" and "racing thoughts" vs. depressive rumination. Attending to the patient's experiences is very important. In the psychomotor agitation commonly seen in depression, the "nervous energy" is always overshadowed by a strong sense of exhaustion and manifests as purposeless movements ; in psychomotor acceleration, however, the excess in movement stems from an abundance of energy and is often channelled and purposeful. Likewise, in depressive rumination, the patient experiences the repetitive thoughts as heavy, leaden, and plodding; in psychic acceleration, however, the thoughts move in a rapid progression, with many themes, rather than a singular one, being touched upon. Even when such experiences are accounted for on the basis of depression, the possibility does still exist, however, that the depressive episode may be complicated by other manic or hypomanic symptoms, in which case it is often prudent to attend to the patient's personal and family history to determine whether or not the patient has bipolar disorder.
