Some of the soldiers who fought in Iraq may have trouble putting the war behind them. They may suffer from post-traumatic stress disorder, or P.T.S.D. But a study of some soldiers in the special forces units showed why they might not. Researchers discovered that during rigorous training exercises, the elite soldiers produced more of a brain chemical called neuropeptide-y than non-special forces troops. They also found that, the more neuropeptide-y they generated, the less likely they were to be distressed." Still, they wonder if there might be a pharmaceutical way to enhance the production of neuropeptide-y and perhaps prevent P.T.S.D. Such a medication would be widely useful because P.T.S.D. is not limited to veterans. Any terrifying event, like natural disasters, car accidents, or violent crime can cause it. Doctors say some drugs are already showing promise in the treatment of P.T.S.D., and they may offer new hope for sufferers of the disorder.