How do DSM-5 criteria differentiate Bipolar I disorder from Bipolar II disorder?

• A. Bipolar I requires at least one manic episode lasting ≥7 days or needing hospitalization; Bipolar II requires hypomanic episode and a major depressive episode, with no full manic episode.
• B. Bipolar I is defined by chronic depressive episodes only.
• C. Bipolar II requires at least one manic episode lasting seven days or hospitalization.
• D. Bipolar I requires at least depressive episodes only.

Answer: (D)

The difference hinges on manic versus hypomanic episodes and the presence of a major depressive episode. In DSM-5, Bipolar I disorder is defined by at least one manic episode. A manic episode is a distinct period of abnormally elevated, expansive, or irritable mood with increased energy, lasting at least seven days (or any duration if hospitalization is needed). During this time, you typically see inflated self-esteem or grandiosity, decreased need for sleep, pressured speech, racing thoughts, distractibility, and risky or impulsive behavior, with clear impairment or need for hospitalization; psychotic features can occur but aren’t required.

Bipolar II disorder requires at least one hypomanic episode and at least one major depressive episode, with no history of a full manic episode. A hypomanic episode lasts at least four days and involves similar symptoms to mania but is milder and does not cause marked impairment or hospitalization, nor does it include psychotic features. A major depressive episode involves at least five symptoms (including either depressed mood or anhedonia) for two weeks or more, with noticeable distress or impairment.

So, the defining distinction is that Bipolar I centers on a full manic episode, while Bipolar II involves hypomanic episodes plus major depressive episodes, without a full manic episode.