From VOA Learning English, this is the Health Report.

　　An international team of researchers has developed a drug that could help in the treatment of post-traumatic stress disorder. PTSD is a mental condition that can develop when someone seize a disturbing event, or serious of events.

　　People who suffer from it experience increased anxiety, depression and may have problems with their memory. Scientists say the drug could be given to someone immediately following a trauma to prevent the development of PTSD.

　　Raul Andero Gali is a researcher at Emory University in Atlanta, Georgia, who studies the biology of PTSD. He says it is the only mental disorder that has a known trigger or cause, such as a car accident, or being in armed conflict. And this means researchers have a better chance of finding a treatment for it.

　　"So we can even define more clearly which is the stimulus or the stressor that trigger[s] the disease, whereas with other psychiatric diseases it is way more difficult. For example, with depression or schizophrenia it is more uncertain what is triggering that disease."

　　Doctor Gali and other researchers at Emory, the University of Miami in Florida, Scripps Research Institute in Florida and the Max Planck Institute of Psychiatry in Munich, Germany worked to find gene associated with the development of PTSD.

　　They found that in some people experiencing a high degree of stress, a gene called OPRL1 releases a protein receptor for a molecule called nociceptin in the brain. Doctor Gali says when that happens, people experience symptoms of post-traumatic stress disorder.

　　The researchers experiment it on mice to develop a drug that blocks the receptor, reducing symptoms of anxiety and fear. Doctor Gali says investigators tested their drug, called SR8993, in mice train to feel an electric shock whenever they heard a specific sound. The mice became very stressed when they heard the sound. Doctor Gali says immediately after the sound and shocks, some of the mice were given SR8993, others were given a drug with no active ingredient called a placebo.

　　"The day after the animals were tested to see how afraid they were for the tone. And the animals that got the compound SR8993 presented less fear to the tone. So their conservation of fear memories is decreased."

　　Doctor Gali says much work needs to be done to determine if SR8993 is effective in humans. If it is, he believes it could be given to, for example, soldiers returning home from a war zone to keep them from developing PTSD.

　　An article on this possible treatment for post-traumatic stress disorder is published in the journal Science Translational Medicine.

　　And that's the Health Report, I'm Christopher Cruise.