Dewleen attended Stanford University, Palo Alto, California, where she received her B.A. in 1968.
She spent one year in Thailand as a Peace Corps volunteer at the Petchburi Teachers College.
She attended medical school at Columbia University College of Physicians and Surgeons (1981), New York, New York. She received her medical degree in 1981 from Columbia University.

Until recently Dr. Baker was an Associate Professor of Clinical Psychiatry in the Department of Psychiatry at the University of Cincinnati in Ohio.

Currently she is Associate Professor at UCSD and Associate Director for Clinical Affairs of the Veterans Affairs Center for Stress and Mental Health located at the VA in San Diego, California