ptsd Can A Hormone Injection Reverse Ptsd? -- Va Starts Testing

[jessejames]

http://www.dallasnews.com/sharedcontent/dw...n1.3ec50b2.html

Injections might help treat post-traumatic stress disorder

After UT Southwestern study, Dallas VA testing hormone on veterans

05:41 AM CDT on Wednesday, September 13, 2006

By SUE GOETINCK AMBROSE / The Dallas Morning News

A simple injection can ease the anxiety that comes with reliving a traumatic memory, according to a new study on mice conducted by Dallas researchers. Scientists at the Dallas Veterans Affairs Medical Center are testing whether a similar medication can relieve post-traumatic stress disorder.

An estimated 5.2 million Americans suffer from the disorder. Combat, an assault or a natural disaster can trigger the condition, which can persist for months or years. Available treatments include psychotherapy and counseling, but no definitive medication exists.

In the new study, scientists at UT Southwestern Medical Center tried to simulate post-tramautic stress disorder in lab mice. The researchers placed mice in a box and gave them a mild but unpleasant electric shock to the feet. When the mice were placed in the box again – with no electric shock – they froze in fear. But when the mice were given an injection of a natural stress hormone, their fear decreased.

The researchers "have made an important discovery that might give us a new therapeutic approach to treating phobias and post-traumatic stress disorder," David Sweatt, a neuroscientist and memory researcher at the University of Alabama at Birmingham, wrote in an e-mail.

The research, appearing in today's issue of the Journal of Neuroscience, stemmed from previous studies showing that people with the disorder have lower-than-normal surges of a stress hormone, corticosterone. That suggested that the hormone – part of the body's biochemical arsenal for dealing with stressful situations – might normally help counteract the anxiety brought on by traumatic memories.

Based on the new mouse tests, that idea seems to be holding up, said Dr. Craig Powell, the UT Southwestern neuroscientist who led the study. The corticosterone injections, he said, seem to help the brain replace the old memory – that the box means an electric shock – with a new one that says the box is now safe.

"We're not erasing the memory, but we're saying, 'Hey, this isn't so bad,' " Dr. Powell said.

Dr. Powell and his colleagues found that the timing of the injection was key. The injection had to be given right after triggering the box-shock memory, he said. Giving the injection before putting the mouse in the box, or without putting the mouse in the box, had no effect.

Based on the mouse experiments, it may be that people prone to post-traumatic stress disorder don't, for whatever reason, extinguish the fear associated with their memories because they don't produce enough corticosterone, said Dr. Robert Greene, a UT Southwestern psychiatrist and neuroscientist who participated in the study. If that's the case, then giving stress hormone injections just after reliving a traumatic memory might help treat the disorder.

Dr. Greene said researchers hope to replace the "malfunction" in the brain.

"Under normal conditions, the hormone system enhances its own extinction of a fear memory," he said. "What's abnormal is when the extinction doesn't happen."

The Dallas VA Medical Center has enrolled about 20 veterans with combat-related post-traumatic stress disorder, giving some of them a stress hormone injection and the others a placebo after triggering traumatic memories. At this point, the researchers don't know which veterans are getting which injection. When the study is complete, the researchers will figure out who got the medication and see whether it was helpful in treating the disorder.

The other UT Southwestern researchers involved in the study were Wen-Hui Cai, Jacqueline Blundell and Jie Han. Dr. Cai and Dr. Greene are also on staff at the Dallas VA Medical Center.

Edited September 14, 2006 by jessejames