Which disorder is characterized by episodes of depression and mania?

Bipolar disorder is characterized by the presence of episodes that alternate between depression and mania. In this condition, individuals experience periods of extreme mood changes, which include depressive episodes that can mirror the symptoms of major depressive disorder, such as persistent sadness, hopelessness, and a lack of interest in activities. In contrast, the manic episodes signify a distinct state of elevated mood, increased energy, and often impulsive behavior.

The alternating nature of these mood episodes is a defining feature of bipolar disorder and distinguishes it from other psychiatric conditions. For instance, major depressive disorder solely involves depressive symptoms without the accompanying manic phases, whereas anxiety disorders primarily focus on excessive worry and nervousness rather than extreme mood fluctuations. Schizophrenia involves a different spectrum of symptoms, including delusions and hallucinations, rather than mood disturbances. Thus, the specific combination of both depressive and manic episodes is what identifies bipolar disorder as the correct answer.