Dr. Cassie Kosarek is a psychiatrist located in Hanover, NH. She is licensed to practice medicine in both New Hampshire and Vermont, and she welcomes patients ages 16 and up from both states.

Dr. Kosarek is a 2012 graduate of Bryn Mawr College, where she majored in English and minored in psychology. After a brief career in medical editing, she completed the Bryn Mawr Postbaccalaureate Premedical Program for career changers and enrolled in the Geisel School of Medicine at Dartmouth College, from which she graduated with her MD in 2021. She completed her General Psychiatry residency at the University of Vermont Medical Center in 2025, serving as co-chief resident during her final year.

During her residency, Dr. Kosarek developed special interests in trauma and transition-age youth, though she treats patients with a wide variety of diagnoses, including depressive disorders, anxiety disorders, bipolar spectrum disorders, eating disorders, and psychotic disorders. As a VA track resident, she spent two years of her residency working with veterans at the Burlington Lakeside Clinic VA, where she became adept at managing PTSD and trauma-related symptoms. She also carried patient panels of both undergraduate and medical students while in residency, helping students navigate mental health treatment as they moved through their academic programs.

Dr. Kosarek considers the “whole person” when formulating treatments, evaluating not only clinical symptoms, but also social and economic contexts, important relationships, personality, strengths, and history. She recognizes that no two brains or stories are alike and that individualization is the key to successful treatment. Her warm, patient-centered approach seeks to meet patients in their present moments, inviting them then to team up with her as they pursue their treatment goals.