Complex sentence: Bipolar disorder or bipolar affective disorder (historically known as manic-depressive disorder) is a psychiatric diagnosis for a mood disorder in which people experience disruptive mood swings that encompass a frenzied state known as mania (or hypomania) and, usually, symptoms of depression.
Split into simpler sentences: Bipolar disorder or bipolar affective disorder (historically known as manic-depressive disorder) is a psychiatric diagnosis for a mood disorder in which people experience disruptive mood swings. These encompass a frenzied state known as mania (or hypomania) and, usually, symptoms of depression.