Ziv J. Cohen, MD, is the Founder and Medical Director of Principium Psychiatry, a multidisciplinary psychiatric company specializing in mood and anxiety disorders, interventional psychiatry, and forensic psychiatry. A board-certified psychiatrist and forensic psychiatrist, Dr. Cohen has particular expertise in the evaluation and treatment of complex mood and anxiety disorders, including treatment-resistant depression.

Dr. Cohen founded Principium Psychiatry to provide sophisticated, evidence-based psychiatric care that integrates psychopharmacology, psychotherapy, measurement-informed treatment, and advanced interventions including TMS, ketamine, Spravato, and ECT. Principium also provides forensic psychiatric evaluations, bringing rigorous diagnostic assessment and psychiatric expertise to legal and occupational questions.

In addition to his clinical and forensic work, Dr. Cohen is involved in physician education, quality improvement, and the development of clinical systems that improve outcomes for patients with complex psychiatric illness. His teaching focuses on practical, evidence-based decision-making in mood disorders, anxiety disorders, treatment-resistant depression, interventional psychiatry, and forensic psychiatry.