Dr. Gallagher received his Ph.D. in clinical and quantitative psychology from the University of Kansas. His research interests include evaluating the efficacy of transdiagnostic treatments for PTSD and anxiety disorders, identifying mechanisms of change of empirically supported treatments, and understanding how positive thinking (e.g., hope, optimism, self-efficacy) promotes well-being and provides resilience to PTSD and other anxiety disorders. He is the author of over 80 articles, chapters and books and is a licensed clinical psychologist.