Hypergraphia is a condition in which a person feels an overwhelming compulsion to write. People with bipolar disorder, especially during mania or hypomania, may find themselves writing for hours at a time, not necessarily realizing that this is unusual. It may take the form of journalling, creative writing, or copying page after page of a book.
Hypergraphia may also be associated with temporal lobe epilepsy and schizophrenia, as well as certain brain injuries.
In an article in Psychology Today, Orli Van Mourik lists Sylvia Plath, who had bipolar disorder, and Danielle Steel, whose book His Bright Light is about her son's bipolar disorder, as famous hypergraphics.
Pressured speech is thought to be related to hypergraphia in bipolar disorder.
A person with hypergraphia is said to be hypergraphic.