6 Recent studies using such techniques include work by Matthews et al57 who used DTI and fMRI to examine the structural and functional neural correlates of major depressive disorder (MOD) in OEF/OTF war veterans with self-reported histories of mild TBI. Those with MDD showed greater activation in the amygdala and other emotional processing structures, lower Inhibitors,research,lifescience,medical activation in emotional control structures, and lower fractional anisotropy in several white matter tracts. Using FDG-PET and neuropsychological testing, Peskind and colleagues51 compared results from 12 OIF veterans with mild TBI and/or PTSD to community volunteers. A decreased cerebral metabolic rate of glucose

in the cerebellum, vermis, pons, and medial temporal

lobe as well as subtle cognitive impairments (eg, verbal fluency, cognitive processing speed) were noted Inhibitors,research,lifescience,medical in the veteran sample. Study limitations as described by the authors included the control group being 21 years older than the veteran group, and 10 out of the 12 veterans having a history of co-occurring PTSD. Readers are encouraged to review the following for more through discussions of functional imaging Inhibitors,research,lifescience,medical techniques and TBI: Bélanger et al,54 Niogi and Mukherjee,57 Wortzel et al,59 and Van Borgen et al.36 Newer techniques such as those described above are frequently unavailable to practitioners. Moreover, based upon the current state of knowledge regarding these measures, significant controversy exists regarding whether Inhibitors,research,lifescience,medical they can appropriately be used in clinical settings.59

In a recent. Letter to the Editor, Adinoff and ATM Kinase Inhibitor nmr Dcvous60 suggested that at present there is an absence of empirical evidence to support using SPECT to diagnose and treat psychiatric illnesses. Inhibitors,research,lifescience,medical This assertion is consistent, with opinions expressed by Niogi and Mukherjee57 who stated that “because of substantial overlap in the range of DTI metrics between age-, gender-, and education matched controls and mild TBI patients, diagnostic interpretation in the individual patient these relying solely on DTI results remains problematic” (p 251). PTSD Garfield and Liberzon50 elegantly summarize neuroimaging studies among those with PTSD, by highlighting the convergence of findings regarding the amygdala, anterior cingulate cortex (ACQ, medial prefrontal cortex, insula, and hippocampus. The authors note that, that findings “lend tentative support to a neurocircuity model that emphasizes the role of dysregulation in threat-related processing” (p 379). A selection of specific structural and functional findings in support, of this model are provided below. In terms of structural imaging, findings suggest, that PTSD is related to reduced hippocampal and ACC volumes.50 Reported bilateral reductions in hippocampal volume have ranged from between 5% and 26%62.