How can major depressive disorder be distinguished from bipolar depression?

• A. Bipolar depression is characterized by mood swings without manic episodes.
• B. Presence of a manic or hypomanic episode distinguishes bipolar from unipolar MDD.
• C. Bipolar depression lacks sadness.
• D. MDD includes psychosis while bipolar does not.

Answer: (B)

The defining idea is that bipolar depression is marked by a history of manic or hypomanic episodes, whereas unipolar major depressive disorder is not. A manic episode involves a distinct period of abnormally elevated or irritable mood with unusually increased energy, lasting at least 7 days (or any duration if hospitalization is needed), plus symptoms like inflated self-esteem, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased goal-directed activity, and risky behaviors. A hypomanic episode has similar features but is less severe and doesn’t cause marked impairment or hospitalization. If a person has never had mania or hypomania, their depressive episodes point to major depressive disorder. Psychotic features can occur in both conditions, so they don’t reliably distinguish them.