What describes manic episodes in bipolar disorder?

Manic episodes in bipolar disorder are characterized by high levels of energy and elevated mood. Individuals experiencing a manic episode may exhibit increased activity, impulsive behaviors, racing thoughts, and often engage in activities that may lead to risky situations. This state can include extreme enthusiasm, irritability, and a reduced need for sleep, all of which indicate a significant shift from their normal functioning.

The other options do not align with the characteristics of a manic episode. Periods of deep sleep and low energy states contradict the elevated energy and activity typical of mania, while consistent happiness oversimplifies the complex emotional states associated with such episodes, which can also include irritability or euphoria. Thus, the correct answer represents the true nature of manic episodes effectively.