PTSD-related differences in resting-state functional connectivity and associations with sex hormones

Background: Posttraumatic stress disorder (PTSD) is a debilitating condition that disproportionately impacts individuals who are female. Prior research indicates that males with PTSD exhibit hypoconnectivity of frontal brain regions measured with resting electroencephalography (EEG). The present study examined functional connectivity among females with PTSD and trauma-exposed controls, as well as the impact of sex hormones. Methods: Participants included 61 females (Mage = 31.41, SD = 8.64) who endorsed Criterion A trauma exposure. Resting state EEG data were recorded for five minutes in the eyes open position. Using a Linear Mixed Effects model, paired region-of-interest power envelope connectivity of the theta band (4-7 Hz) served as the response variables. Results: Compared to controls, the PTSD group displayed hyperconnectivity between visual brain regions and the rest of the cerebral cortex (pFDR < 0.05). Additionally, participants with PTSD demonstrated enhanced connectivity between the default mode network and frontoparietal control network compared to controls (pFDR < 0.05), as well as increased connectivity between the ventral attention network and the rest of the cerebral cortex (pFDR < 0.05). Estradiol was associated with higher connectivity, while progesterone was associated with lower connectivity, but these did not survive correction. Conclusions: Results are consistent with prior research indicating that PTSD is associated with altered connectivity in visual brain regions, which may reflect disrupted visual processing related to reexperiencing symptoms (e.g., intrusive memories). Our findings provide additional support for the relevance of the theta frequency range in PTSD given its role in fear learning and regulation processes.