Post Traumatic Stress Disorder (PTSD) is an anxiety disorder that can occur after someone experiences a traumatic event that caused intense fear, helplessness, or horror. PTSD can result from personally experienced traumas (e.g., rape, war, natural disasters, abuse, serious accidents, and captivity) or from the witnessing or learning of a violent or tragic event.

While it is common to experience a brief state of anxiety or depression after such occurrences, people with PTSD continually re-experience the traumatic event; avoid individuals, thoughts, or situations associated with the event; and have symptoms of excessive emotions. People with this disorder have these symptoms for longer than one month and cannot function as well as they did before the traumatic event. PTSD symptoms usually appear within three months of the traumatic experience; however, they sometimes occur months or even years later.

Here are some links for more information:

PTSD in children and adolescents

PTSD symptoms and treatment options.

 PTSD and Art Therapy