Dr. Nissen is a Harvard Medical School-trained physician and therapist that specializes in treating ADHD and anxiety disorders. He also has expertise in treatment-resistant depression and substance use disorders (marijuana, nicotine/vaping), as well as young adults struggling with the transition to adulthood.

He started his concierge clinic after seeing countless patients and families disillusioned with the behavioral healthcare model commonly available: short, infrequent, med-focused visits with minimal impact. His dedication to a small number of patients allows him to provide quality, attention and direct accessibility for clients.

Dr. Nissen is passionate about the mind-body connection and takes a bio-psycho-social approach with each person, implementing evidence-based biological (e.g., medical, sleep, diet, exercise), psychological (e.g., therapy, exposure, learning) and social (e.g., relationships, career, spiritual) interventions.

He hosts the Brain Health with Dr. Nissen podcast and is an ABC News reporter where he explores the latest research on sleep, supplements, diet, exercise, and other lifestyle interventions for mental illness.

​Dr. Nissen attended Brown University's Warren Alpert Medical School and trained in psychiatry at Harvard Medical School. While at Harvard, he was Chief Resident of Student Mental Health and researched non-stimulant treatments for ADHD.

Dr. Nissen worked as a cognitive behavioral and exposure therapist at the Boston University Center for Anxiety and Related Disorders (CARD) and is certified as a CBT Therapist through the Feeling Good Institute. He is also a trained practitioner of the Apollo ReCODE 2.0 dementia prevention and reversal protocol.

Dr. Nissen has expertise in psychedelics and interventional psychiatry. He trained in ketamine-assisted psychotherapy (KAP) with Psychedelic Therapy Boston; ketamine infusions, TMS, and Spravato at the Massachusetts General Hospital; and MDMA-assisted therapy with MAPS.

Dr. Nissen is a husband and father, and is passionate about helping people overcome adversities to achieve their personal and professional dreams.