Other specified bipolar and related disorders are diagnosed by exclusion of the previous three. The diagnosis can include cases with hypomania in the absence of major depression, insufficient duration of episode, not quite enough symptoms to meet the formal definition, and brief (eg, approximately 6 months) cyclothymic presentations. Clinically, 2- or 3-day hypomanias are common, and do not appear to differ meaningfully from full-duration hypomania. Episodic presentation of symptoms is more suggestive of mood disorder than more chronic histories of the same symptoms.