Which symptoms define bipolar type 2?

Bipolar type 2 is characterized by the presence of at least one hypomanic episode and at least one major depressive episode. Specifically, a hypomanic episode lasts a minimum of four consecutive days and involves an elevated or irritable mood, increased activity or energy, and changes in functioning that are noticeable but not severe enough to require hospitalization or cause significant impairment.

The defining feature of bipolar type 2 is that while individuals experience hypomanic episodes, they do not experience the full-blown manic episodes typical of bipolar type 1. Additionally, individuals with bipolar type 2 often face significant depressive episodes that can impact their ability to function normally, distinguishing the disorder from milder mood fluctuations.

In this context, symptoms from other conditions or episodes do not align with the criteria for bipolar type 2. A manic episode alone is indicative of bipolar type 1, while depressive episodes without hypomania are suggestive of unipolar depression. Moreover, mixed episodes, which involve symptoms of both mania and depression occurring concurrently, do not specifically fit the diagnostic criteria for bipolar type 2 but may indicate type 1 or other mood disorders.