| Post-traumatic stress disorder (PTSD), which falls under the rubrique of an anxiety disorder, is a clinical syndrome resulting from experiencing or witnessing an extreme traumatic stressor. DSM-IV distinguishes between three different subtypes of PTSD according to the time of onset and duration of the symptoms: acute, chronic, and delayed onset PTSD. Although delayed onset PTSD is uncommon, a number of studies indicate that the initial onset of PTSD may occur many months or years after the original traumatic event.;Research in the realm of PTSD has provided evidence that there are anatomical, functional, and biochemical differences in the central nervous systems of individuals with PTSD compared with normal control subjects. However, thus far, studies have not sought to distinguish between and compare delayed onset and immediate onset PTSD along these dimensions. The present study utilized SPECT technology to investigate cerebral blood flow in Vietnam veterans with immediate onset PTSD, delayed onset PTSD, and a PTSD negative control group. The results indicated that both experimental groups demonstrated statistically significant differences in cerebral blood flow in numerous regions of the brain relative to the control group. In addition, the PTSD delayed onset and immediate onset subjects presented with distinct perfusion profiles. The implications of these findings were discussed in terms of differentiating between delayed and immediate onset PTSD and PTSD symptomatology. |
