Post-traumatic stress disorder is, technically, an anxiety disorder; however, the experience (and cause) of PTSD can differ from the more generalized anxiety disorders. PTSD occurs when there has been a traumatic experience in the life of an individual in which he/she felt endangered, and over which he/she had little- to no- control (e.g., a crime, a motor-vehicle accident, a safety-threatening encounter with nature, the experience of abuse as a child). The markers of PTSD include:

• re-living the event in one's thoughts
• determined avoidance of factors that remind one of the event or could lead to feelings of re-endangerment
• the experience of nightmares
• the experience of panic reactions

Sometimes, the individual feels debilitated by a sense of life "closing in," or by a specific sense of fear, or avoidance, but he/she does not always make a direct connection between the symptoms and the original trauma. This is particularly true when the symptoms occur in adulthood, but the trauma occurred in childhood.