Andrew Tatarsky, Ph.D., holds a doctorate in clinical psychology from City University of New York. He has a private practice in New York City specializing in harm reduction psychotherapy with drug and alcohol users and is co-director, with Dr. Mark Sehl, of the Harm Reduction Psychotherapy and Training Associates, a treatment and training organization. His perspective on substance use problems has evolved over twenty years of experience working in the area as psychotherapist, supervisor, program director, teacher, writer, and public speaker. He is a founding member and Past President of the Addiction Division of the New York State Psychological Association and Chairperson of Mental Health Professionals in Harm Reduction.