Selective serotonin reuptake inhibitors are the usual first level pharmacological treatment for PTSD [17] [18] [19] [20] [21] [22] . Other lines of drugs, such as benzodiazepines and monoamine oxidase inhibitors, are also commonly used [23] . However, the effects of these pharmaceuticals are not always satisfactory [23] [24] [25] , and undesirable side effects such as sleep disturbance, sexual dysfunction, and dizziness have been reported [23, [26] [27] [28] [29] .