Post traumatic stress disorder (PTSD) develops after exposure to a stressful or traumatic situation, such as happens to accident victims, abuse survivors and combat veterans. PTSD symptoms (e.g., flashbacks) may not begin immediately after the event or may recur months or even years later. When PTSD lasts three months or longer, it is called chronic PTSD. Children can experience PTSD, too. PTSD treatment can include counseling and medication.