Describes the structure and function of neurons, glia, neurotransmitters, and brain regions. Explains how the brain produces and is a ected by anxiety, trauma disorders, and depression. Describes how stress is the foundation for anxiety, PTSD (post-traumatic stress disorder), trauma, and many depressions. Describes the new criteria for the diagnosis of PTSD, trauma disorders, and anxiety disorders. Outlines the symptoms and treatment of the major anxiety disorders, including dental anxiety. Lists the difference in symptoms and treatment of trauma disorders, including PTSD. Explains the nature and course of depression as a co-factor in PTSD, trauma, and anxiety disorders. Describes, for this course, the implications for dentistry, mental health, nursing, and other healthcare professions.