Dr. Desmond was born in New York City. After attending the Kew-Forest School in Forest Hills, New York, he received his A.B. in the Behavioral Sciences from the University of Chicago in 1982 and his Ph.D. in Clinical Psychology from Fordham University in 1990.

Dr. Desmond completed a fellowship in stroke and dementia under Thomas K. Tatemichi, M.D. at the Neurological Institute of New York of the Columbia University College of Physicians and Surgeons and he became a member of the faculty of that institution and principal investigator of the Stroke and Aging Research Project, the largest prospective study of cognitive function in hospitalized stroke patients that has thus far been run, after Dr. Tatemichi's death. Dr. Desmond and his team published numerous widely-cited articles on their findings, reporting that dementia was present in one-fourth of older patients three months after stroke, that incident dementia was common during long-term follow-up among stroke patients who were initially nondemented, and that dementia among stroke patients significantly increased their risk of both recurrent stroke and death. Their studies identified multiple clinical determinants of dementia after stroke, including the location and severity of the presenting stroke, vascular risk factors such as diabetes mellitus and prior stroke, and host characteristics such as older age, fewer years of education, and nonwhite race/ethnicity. Genetic factors were also relevant, particularly in CADASIL, and concomitant Alzheimer's disease played an etiologic role in approximately one-third of cases of dementia after stroke.

Dr. Desmond's first book, a satirical novel based in Palm Beach and Paris entitled The Misadventures of Oliver Booth: Life in the Lap of Luxury (ISBN 978-1-929774-56-2), has been released by the Greenleaf Book Group. It has received the Best Books Award (Humor) from USA Book News, the Next Generation Indie Book Awards for Best General Fiction/Novel and First Novel as well as the Third Place Grand Prize for Fiction, and recognition as a finalist for the 2009 IBPA Benjamin Franklin Award in the Humor/Comedy/Satire category. Dr. Desmond is currently working on his second novel, which will follow the continuing adventures of Oliver Booth as he becomes involved in the world of real estate in Palm Beach and Manhattan, and he writes a weekly humor column for the Palm Beach Daily News.