Which of the following statements about bipolar disorder is true?

Bipolar disorder is characterized by the presence of one or more manic or mixed episodes, which is a defining aspect of the disorder. A manic episode is marked by an abnormally elevated mood, increased activity or energy, and often includes impulsivity and poor decision-making. Mixed episodes, where features of both mania and depression occur simultaneously, highlight the complexity of bipolar disorder. This distinction is crucial because it helps differentiate bipolar disorder from unipolar depression and underscores the need for specific treatment approaches tailored to the manic phases of the disorder.

The other statements do not accurately represent the nature of bipolar disorder. It can indeed occur alongside major depression; this co-occurrence is often seen as individuals with bipolar disorder experience depressive episodes in addition to their manic or hypomanic episodes. While mood changes in bipolar disorder can have seasonal components, it is not solely related to seasonal changes. Additionally, bipolar disorder is a chronic condition that typically requires ongoing treatment and management rather than resolving on its own. Understanding these key features helps in the recognition and effective management of the disorder.