Dr. Rasmussen received his medical training at Brown University. He completed his psychiatric training at Yale University School of Medicine where he was a Biologic Science Training Program Fellow. Since 1983 he has been on the faculty in the Psychiatry Department at the Brown University School of Medicine where he is the Director of the Obsessive Disorders Clinic. Currently he is the medical director at Butler Hospital, a free standing psychiatric facility that is the major psychiatric teaching hospital affiliated with the medical school.

Dr. Rasmussen has been involved in research on a wide range of topics related to obsessive compulsive disorder over the past two decades. These have included studies of the clinical features and course of the disorder, pharmacologic, behavioral and family treatment, family genetic studies, and more recently, neurosurgical approaches to intractable OCD.

Dr. Rasmussen has been the recipient of an Independent Investigator Award from the National Alliance for Research in Schizophrenia and Affective Disorder(NARSAD) and is currently funded by two R-01's from NIMH and industry grants from Medtronic. He has published extensively on the epidemiology, clinical features and treatment of OCD. He is an editorial consultant for a number of journals including Archives of General Psychiatry, Biologic Psychiatry and the American Journal of Psychiatry. He is listed as one of the top 25 cited psychiatrists by Highly Cited.

In addition to his administrative and research responsibilities, Dr. Rasmussen maintains an active specialty practice in OCD, with 20 hours of clinical work weekly. He is the recipient of the Exemplary Psychiatrist Award from the National Alliance of the Mentally Ill (NAMI) and has been recognized in Best Doctors in America yearly since 1997.