Sean Dunn, PMHNP-BC
Board-Certified Psychiatric Mental Health Nurse Practitioner providing online psychiatry care across Washington State
Sean Dunn is a board-certified psychiatric mental health nurse practitioner and the founder of ATC Psychiatry. He provides psychiatric evaluation and medication management to adults, teens, and families throughout Washington State online, with offices in Seattle and Poulsbo.
Education and Training
Sean graduated summa cum laude with a Bachelor of Science in Nursing from Northeastern University, then completed his Master of Science in Psychiatric and Mental Health Nursing at Vanderbilt University, where he received a named scholarship for academic excellence.
He is board-certified by the American Nurses Credentialing Center (ANCC) as a Psychiatric-Mental Health Nurse Practitioner and is licensed as an Advanced Registered Nurse Practitioner in Washington State. He is additionally certified in trauma-informed cognitive behavioral therapy.
Clinical Experience
Sean's clinical background includes training and practice at several nationally recognized institutions:
McLean Hospital, an affiliate of Harvard Medical School
Boston Children's Hospital
Multiple outpatient behavioral health practices in Massachusetts and Washington
He founded ATC Psychiatry in 2021 to make thorough, unhurried psychiatric care available to people across Washington — including the rural and semi-rural communities where access to a psychiatric prescriber has historically meant a months-long wait or a long drive.
Approach to Care
Sean practices with an empathetic, validating, and patient-centered approach. Having been on both sides of the mental health care experience, he emphasizes honesty, mutual respect, and collaboration in every treatment relationship.
His priority in a first appointment is understanding the whole picture — symptoms, history, sleep, stressors, prior treatment, and what has and hasn't worked — before recommending anything. He explains diagnoses and treatment options in plain language so patients can make informed decisions rather than simply receiving instructions.
Sean prescribes conservatively and with a safety-first orientation, and he works collaboratively with therapists, primary care providers, and families when that supports a patient's care.
Conditions Sean Treats
Sean's clinical interests include mood and anxiety disorders, ADHD, OCD, and trauma-related symptoms. He welcomes clients of all ages, backgrounds, orientations, and identities.
Obsessive-compulsive disorder (OCD)
Post-traumatic stress and trauma-related symptoms
Bipolar disorder
Sleep difficulties and insomnia
See the full list on our conditions we treat page.
Where Sean Practices
All appointments are conducted by secure telehealth, so Sean sees patients anywhere in Washington State. He is based in Seattle and also practices from ATC Psychiatry's Poulsbo office.
Patients commonly connect from Seattle, Bellevue, Tacoma, Everett, Poulsbo, Bainbridge Island, Spokane, and across the state.
Insurance and Rates
ATC Psychiatry is in network with major Washington insurance plans and also sees self-pay patients. See current rates and accepted insurance, or read what to expect at your first appointment.
Outside the Office
Sean spends his free time outdoors in the Pacific Northwest, writing and reading genre fiction, replaying '90s video games, and listening to mental health podcasts while walking his dog. He remains willing to discuss, at length, the final season of Game of Thrones.
Schedule with Sean
Sean is currently accepting new patients. No referral is required. New patients can book directly through our secure portal.
Meet the rest of our Washington providers
If you are in crisis or thinking about harming yourself, call or text 988 to reach the Suicide and Crisis Lifeline, available 24 hours a day. If you are in immediate danger, call 911.
NPI 1528739653 · Washington ARNP license. Last updated August 2026.