RT Journal A1 Shin LM, Lasko NB, Macklin ML, et al T1 REsting metabolic activity in the cingulate cortex and vulnerability to posttraumatic stress disorder JF Archives of General Psychiatry JO Archives of General Psychiatry YR 2009 FD October 1 VO 66 IS 10 SP 1099 OP 1107 DO 10.1001/archgenpsychiatry.2009.138 UL http://dx.doi.org/10.1001/archgenpsychiatry.2009.138 AB Context  Recent neuroimaging research has revealed functional abnormalities in the anterior cingulate cortex, amygdala, and hippocampus in individuals with posttraumatic stress disorder (PTSD).Objective  To determine whether resting functional abnormalities found in PTSD are acquired characteristics or familial risk factors.Design  Cross-sectional design including identical twins discordant for trauma exposure.Setting  Academic medical center.Participants  Combat-exposed veterans with PTSD (n = 14) and their identical co-twins not exposed to combat (n = 14) as well as combat-exposed veterans without PTSD (n = 19) and their identical co-twins not exposed to combat (n = 19).Main Outcome Measures  We used positron emission tomography and fluorodeoxyglucose 18 to examine resting regional cerebral metabolic rate for glucose (rCMRglu).Results  Veterans with PTSD and their co-twins had significantly higher resting rCMRglu in the dorsal anterior cingulate cortex/midcingulate cortex (dACC/MCC) compared with veterans without PTSD and their co-twins. Resting rCMRglu in the dACC/MCC in unexposed co-twins was positively correlated with combat exposure severity, PTSD symptom severity, and alcohol use in their exposed twins.Conclusions  Enhanced resting metabolic activity in the dACC/MCC appears to represent a familial risk factor for developing PTSD after exposure to psychological trauma.