How many episodes of hypomania or mania are necessary for a diagnosis of bipolar disorder?

For a diagnosis of bipolar disorder, the presence of at least one episode of hypomania or mania is a fundamental criterion. This requirement aligns with the definition of Bipolar I Disorder, in which individuals must have experienced at least one manic episode, which can be preceded or followed by hypomanic or major depressive episodes, but not necessary.

The diagnostic criteria, as outlined in the DSM-5, specify that for bipolar disorder to be diagnosed, the manic or hypomanic episode must involve distinct periods of elevated, expansive, or irritable mood and must last for at least one week (or any duration if hospitalization is necessary). While multiple episodes can occur, only one is required for diagnosis, thereby emphasizing the significance of the manic episode in establishing the disorder.

In contrast, additional episodes may delineate the specific subtype of bipolar disorder or provide information about the episode severity and frequency, but they are not a prerequisite for the diagnosis itself. Thus, the correct understanding is that only one such episode is necessary to meet the criteria for bipolar disorder.