PTSD is a very difficult condition to live with, particularly in the acute stages, because their autonomic nervous system has been re-set to over-react, and just about everything triggers the intense dread and panic of the traumatic event as if it were happening again. People have flashbacks, nightmares, depression, anxiety, irritability and anger, insomnia, hyper-vigilance responses, hyper-startle responses, and more. There are many therapeutic approaches, one of which is to desensitize oneself to the triggering stimuli by gradual exposure to it. In addition to PTSD, this technique can be used to desensitize oneself to phobias (fear of flying, fear of snakes, etc.) and social anxiety disorder.