Susanna Kaysen is an American author, best known for her 1993 memoir Girl, Interrupted. Born on November 11, 1948, Kaysen was raised in Cambridge, Massachusetts. She attended high school at the Commonwealth School in Boston and the Cambridge School before being sent to McLean Hospital in 1967 to undergo psychiatric treatment for depression. There, she was diagnosed with borderline personality disorder and was released after eighteen months.

Kaysen's experience at McLean Hospital inspired her to write Girl, Interrupted, a memoir that was later adapted into a film in 1999, with her role being played by Winona Ryder. She is the daughter of economist Carl Kaysen, a professor at MIT and former advisor to President John F. Kennedy. Her mother, now deceased, was the sister of architect Richard Neutra. Kaysen also has one sister.