Which of the following is a symptom of a manic episode?

A manic episode is characterized by an abnormally elevated, expansive, or irritable mood, alongside a range of other symptoms. One of the hallmark features of mania is the tendency for individuals to engage in excessive involvement in high-risk activities. This behavior reflects an impulsive and irresponsible approach to life situations and can lead to negative consequences; for instance, spending sprees, sexual indiscretions, or reckless driving.

The other options, such as low energy, increased sleep, and withdrawn behavior, are more indicative of depressive episodes rather than manic episodes. Individuals experiencing a manic phase show heightened energy levels, decreased need for sleep, and often an increased drive to engage socially and take on new projects or experiences. Therefore, involvement in high-risk activities aligns strongly with the symptomatology of mania in the DSM-5-TR.