Post-Traumatic Stress Disorder (PTSD): A condition triggered by traumatic events, leading to flashbacks, nightmares, and emotional distress. Specialists: Psychiatrists, Psychologists, Trauma Therapists, Cognitive-Behavioral Therapists. Diagnosis: Based on DSM-5 criteria, clinical interviews, and tools like the PTSD Checklist (PCL-5). Symptoms include hypervigilance, avoidance, and emotional numbness.