 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 experiences a disturbing event or series 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 after a trauma to prevent the development of PTSD. Raul Endero Gali is a researcher at Emory University in Atlanta, Georgia, who studies PTSD. He says it is the only mental disorder with a known trigger, such as a car accident or armed conflict. This means researchers have a better chance of finding a treatment. Dr. Gali and researchers at several other institutions have worked to find a gene linked to PTSD. They found a gene called OPRL1, which releases a protein receptor in the brain of some people under stress. Dr. Gali says this receptor can cause people to experience symptoms of PTSD. The researchers experimented on mice to develop a drug that blocks the receptor and reduces anxiety and fear. Dr. Gali says investigators tested the drug called SR8993 in mice, trained to fear an electric shock whenever they heard a specific sound. The mice became stressed when they heard the sound. Dr. Gali says immediately after the sound and shocks, some of the mice were given SR8993. Others were given a placebo, an inactive substance. Dr. Gali says the mice that got the drug showed less fear to the tone. He adds, however, that more work is needed to find out if it is effective in humans. For VOA Learning English, I'm Carolyn Presuti.