Simeon is a graduate of Columbia University's medical school, psychiatry residency and fellowship program, and psychoanalytic institute.
[citation needed] Simeon was an associate professor of psychiatry at the Mount Sinai School of Medicine in New York City, where she did research, supervised, and taught.
She also co-chaired an international task force that generated new recommendations for the DSM-V classification of dissociative disorders.
[citation needed] With editor and magazine writer Jeffrey Abugel, Simeon co-authored the book Feeling Unreal: Depersonalization Disorder and the Loss of the Self (ISBN 0-19-517022-9), published by Oxford University Press in 2006.
It presents a distillation of the scientific research on this disorder, the philosophical and literary references, as well as current treatment options.