Advances in neuroimaging permit in vivo investigation of the structural and
functional neurobiology of post-traumatic stress disorder (PTSD). Recent reviews of
structural and functional neuroimaging in PTSD are discussed together with recent
studies. The significance of the findings is limited by the disparate groupings of PTSD
trauma exposures, making generalization difficult, and this, combined with the
heterogeneity inherent in the existing diagnostic criteria, renders the often conflicting
data confusing. There has been an emphasis on studies of cortical structures, without
adequate consideration of neural circuit models implicating other brain structures. There
has been a move towards investigating subsets of symptoms, such as hyperarousal and
dissociation, particularly in functional imaging studies. Overall, neuroimaging research
in PTSD faces challenges for the future. The key improvements lie in: the definition and
classification of trauma exposures, as they are not all equivalent in nature or indeed
comparable; the study of restricted phenotypic subsets of symptoms or endophenotypes,
such as hyperarousal and dissociation which may have different neural substrates;
adequate study designs for power and control of confounders; and more focused research
based upon targeted investigation of neural networks putatively involved in the
processing and re-experiencing of trauma.
