Responding to Individuals with Mental Illnesses is designed as a guide for recognizing mental illnesses and responding to people affected by these disorders, especially during times of crises. The text describe the signs and symptoms of a variety of psychiatric illnesses, substance use disorders, and developmental disabilities, especially those that may be most frequently encountered by first responders and public safety officials, as well as professionals in the criminal justice system. Many of the chapters deal with specific categories of mental illnesses and provide basic skills to enhance interactions with people with these disorders who may be facing stressful situations. This is not a comprehensive textbook about psychiatric disorders, but rather a practical guide that aims to enhance knowledge and skills for non-mental health professionals who interact with individuals with such illnesses.