Neuromarkers of post-traumatic stress disorder: A systematic review of positron emission tomography studies.

Posttraumatic stress disorder (PTSD) is a severe mental health condition that can arise following exposure to a traumatic event. The identification of biomarkers using imaging techniques, such as positron emission tomography (PET) scans, offers an alternative to increasingly complex diagnostic approaches. This systematic review aims to assess and summarise the evidence for molecular biomarkers in PTSD. Studies published before June 2025 that examined brain changes using PET imaging in adult PTSD patients, were identified from three electronic databases. Inclusion criteria included original human studies, a PTSD diagnosis, and inclusion of healthy controls (not exposed to trauma) and/or trauma-exposed controls who did not develop PTSD. Studies with incomplete reporting, non-English publications, and those lacking control groups were excluded. The risk of bias was assessed using the Newcastle-Ottawa Scale. After screening the 1102 retrieved articles, 20 met the inclusion criteria. These involved 483 patients and 522 controls, including 426 healthy controls and 96 trauma-exposed controls. PTSD was associated with increased glucose metabolism in the amygdala and dorsal anterior cingulate cortex, alongside hypometabolism of the hippocampus and precuneus. Alterations in neurotransmitter systems, stress and inflammation systems, as well as elevated amyloid-beta accumulation, were also observed in PTSD. This review highlights converging neurobiological alterations in PTSD, including changes in metabolism, neurotransmission, and inflammation. These alterations predominantly involve large-scale brain networks such as the salience network, default mode network, and frontoparietal network, reflecting disruptions in emotion regulation, self-referential processing, and executive control. PET imaging shows promise for improving diagnosis, monitoring treatment response, and informing personalised interventions.