This invention is related to 3-(2-(4-(2-methoxyphenyl)piperazine-1-yl) ethyl) quinazoline-4(3H)-one, pharmaceutically acceptable salts, enantiomers, diasteroisomers, stereoisomers, crystals, hydrates, solvates, prodrugs, and metabolites thereof for the treatment of Post-Traumatic Syndrome Disorder (PTSD), and pharmaceutical compositions containing the compounds for the treatment of Post-Traumatic Syndrome Disorder (PTSD).