the two most widely experienced Trauma and Stressor-Related Disorders are Acute Stress Disorder (ASD) and Post-Traumatic Stress Disorder. Either/both may consist of intrusive thoughts, dreams, or “flashbacks” related to a traumatic, dangerous, or stressful event. Acute Stress Disorder develops right after the event and lasts for days, whereas PTSD may have delayed development and last for months or years.