Manic-depression distorts moods and thoughts, incites dreadful behaviors, destroys the basis of rational thought, and too often erodes the desire and will to live. It is an illness that is biological in its origins, yet one that feels psychological in the experience of it.

Kay Redfield Jamison, An Unquiet Mind: A Memoir of Moods and Madness, New York, 1995, p. 6