She is the Director of the Johns Hopkins Community Psychiatry Out-patient Program. Dr. Cullen is a 1988 graduate of Trinity College Dublin. She completed her general practitioner and psychiatry residencies in St. James Hospital, Dublin and completed research and clinical fellowships at Johns Hopkins Medical Institutions. She joined the faculty at Johns Hopkins in 2001. Her research interests include: service delivery to those with mental health illnesses and obsessive compulsive disorder.