Olfactory identification in combat-related posttraumatic stress disorder

Recent neuropsychological conceptualizations of posttraumatic stress disord er (PTSD) implicate dysfunction of the fronto-limbic system, a brain system thought to be involved in the mediation of emotion. However few studies ha ve examined fronto-limbic subregions, such as the orbitofrontal cortex, in PTSD. As a measure of orbitofrontal integrity olfactory identification was assessed in 26 Vietnam War veterans with PTSD, 25 Vietnam War veterans with out mental disorders, and 17 Vietnam-era, non-war-zone veterans without men tal disorders. Relative to veterans without PTSD, those diagnosed with PTSD were less proficient in odor identification and verbal learning but not on other cognitive tests sensitive to dorsolateral prefrontal and mesial temp oral functioning. Results bolster prior research indicating fronto-limbic d ysfunction in PTSD, and suggest involvement of the orbitofrontal region.