Effect of glucocorticoid administration on brain function in PTSD

After traumatic and life threatening events, up to 10% of people will develop post-traumatic stress disorder (PTSD). Part of this disorder involves repeated flashbacks to the event, or nightmares of it. Those people who develop this may do so partly because the stress hormone system has not been active enough at the time of the event to stop the memories from becoming deeply encoded. The action of stress hormones on such memories is therefore vital. We plan to examine the effects of stress hormones on the brain while people are experiencing such memories. Patients with PTSD secondary to the Canterbury earthquake, and people who have experienced similar trauma in the earthquakes but not developed PTSD, will relive memories of the earthquake while in a brain scanner. The effects of the stress hormone, cortisol, on this process will be examined.