Lessons from the past -- Diagnosis of acute stress disorder -- Acute stress disorder in DSM-5 -- Do initial reactions predict long-term reactions? -- Biology of acute stress reactions -- Cognitive features of acute stress reactions -- Assessing acute stress reactions -- What about psychological debriefing? -- An overview of treatment for acute stress disorder -- How to treat acute stress disorder -- Challenges to treating acute stress disorder -- Mild traumatic brain injury -- Working with military personnel and first responders -- Acute stress disorder in children -- Acute stress disorder and the law.