Trauma is defined as an event that threatens life or well-being and causes intense fear, helplessness or horror. Post-traumatic stress (PTS) involves memories and physical/emotional reactions to trauma without disrupting functioning, while post-traumatic stress disorder (PTSD) features intrusive memories and flashbacks that interfere with thought and social interaction. PTSD symptoms include avoidance behaviors, hyper-arousal, and depression commonly occurs after trauma as well.