How long must hypomanic symptoms last for bipolar type II diagnosis?

In the context of diagnosing Bipolar II Disorder, hypomanic symptoms must persist for at least 4 consecutive days. This duration differentiates hypomania from a manic episode, which is characterized by more severe symptoms and an increased duration of at least 7 days. The requirement for a minimum of 4 days allows for the identification of a distinct episode that affects the individual's functioning but does not meet the criteria for a full manic episode. This criterion ensures that the symptoms are substantial enough to be clinically significant while still reflecting the characteristic nature of hypomania, which is typically less severe than mania. Therefore, the correct answer underlines the importance of the specific duration of symptoms in the diagnostic criteria for Bipolar II Disorder.