After receiving his M.D. degree and completing his residency in adult psychiatry, Dr. Larson received a National Research Service Award and completed a Master of Science (M.S.) degree in Preventive Medicine and Environmental Health (Specializing in Psychiatric Epidemiology), while also supervising the Adult Outpatient Clinic at The University of Iowa Hospitals & Clinics. He then completed an additional two-year Fellowship in Child & Adolescent Psychiatry at Iowa. Dr. Larson then was appointed Assistant Professor of Child Psychiatry at The University of Pittsburgh School of Medicine and The Western Psychiatric Institute & Clinic, Pittsburgh, Pennsylvania.
He subsequently served as Assistant Professor of Psychiatry at The Ohio State University Hospitals and also served as Director of The Child Psychiatry Consultation Service at Children's Hospital, in Columbus, Ohio.
While in Ohio, Dr. Larson met the love of his life and they chose to move to Green Bay to raise their family. Since then, Dr. Larson has served as Medical Director of two different hospitals and was one of the original founders of Riverside Psychiatric, where he continues in private practice. He also continues to serve as a psychiatric consultant to Catholic Charities in Green Bay.