What defines bipolar disorder?

Bipolar disorder is characterized by alternating periods of depression and mania. This means that individuals with the condition experience significant mood swings that include episodes of intense emotional highs (mania or hypomania) and lows (depression). During manic phases, a person may exhibit increased energy, euphoric mood, irritability, and recklessness, while depressive phases can involve feelings of sadness, hopelessness, and a lack of energy or interest in daily activities.

The defining feature of bipolar disorder is the presence of both the manic and depressive states rather than just one. This dual nature of the condition distinguishes it from unipolar depression, which only includes depressive episodes. Thus, the option that describes the alternating periods of depression and mania accurately captures the essence of bipolar disorder, making it the correct answer.