Final answer:
Bipolar disorders typically onset in late adolescence to early adulthood, with the majority of cases beginning between ages 15 and 25. These disorders present with episodes of depression and mania, leading to considerable functional impairment. Bipolar disorder is a significant mental health concern and one of the leading causes of hospitalization due to mood disorders.
Step-by-step explanation:
The onset of bipolar disorders generally starts in late adolescence or early adulthood, most often between the ages of 15 and 25 years. This is according to studies found in the Textbook of psychiatric epidemiology, which detail the epidemiology of bipolar disorder among adults and children. Bipolar disorder is recognized by its alternating periods of depression and mania, previously known as manic depression, causing significant hurdles in everyday functioning for those affected. The impact of bipolar episodes can persist, leading to challenges in areas such as school performance even after the episode has passed.
As one of the more common mental disorders in the United States, mood disorders such as bipolar disorder afflict a significant portion of the adult population annually. It is also one of the leading causes of illness-related hospitalization. While it is important to understand that feeling sad or "blue" occasionally is normal, the depressive episodes associated with bipolar disorder are an enduring, severe illness that often requires medical treatment.