Doctor Ken Kedan is a psychologist working for the Greater Greendale Mental Health Services. He diagnoses Ben Chang as having a new form of amnesia he dubs "Changnesia". He takes Chang to the school hoping to help him recover his lost memories. His first appearance was in the Season Four episode "Alternative History of the German Invasion". He is portrayed by actor Marc Jablon.
In the study group's fourth year at Greendale, Chang unexpectedly shows up on campus and shocks Dean Pelton when he appears in his office. He is accompanied by Doctor Ken Kedan who introduces himself and explains how Chang was discovered wandering around with memory loss, the only hint of his identity being a memo pad page bearing the Greendale logo. On it was written that Chang's name was "Kevin" and that he has "Changnesia". Kedan tells Pelton that he hopes immersive therapy in this familiar environment will jog some memories. The Dean refuses to allow this but The doctor explains he had already cleared it with the school board and leaves Chang in Pelton's custody ("Alternative History of the German Invasion").
Dr. Kedan is later shown participating in a documentary being filmed by Abed chronicling "Kevin"'s amnesia. The film is being used by the school not only as a way of promoting awareness of Chang's plight but also to help secure a grant for further research of it from the MacGuffin Group institute. Chang's condition is now officially referenced as "Changnesia" by Kedan who explains on camera how much more complicated it is compared to normal amnesia. He mentions it's varied and random symptoms and resistance to both practical and alternative methods of treatment. Kedan also points out the unique aspect of "Changnesia" that erases peoples memory but not the ability to make forced puns. He later shoots down Britta's "controversial" theory that Chang had hit his head restoring his original persona of "Kevin" ("Advanced Documentary Filmmaking").
|The name of Doctor Ken Kedan is a nod to Ken Jeong who portrays Ben Chang. Jeong was an actual doctor, a general practitioner, before deciding to become a comedian and actor. At the start of his show business career, Jeong did stand up comedy using the name "Dr. Ken".