Come la scorsa settimana per la rubrica: CERVELLO & TERREMOTO ho presentato l’abstract dell’interessante articolo giapponese Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress uscito lo scorso 22 maggio 2012 sulla Rivista Molecular Psychiatry.Molecular Psychiatry advance online publication 22 May 2012; doi: 10.1038/mp.2012.51
Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress
A Sekiguchi1, M Sugiura1,2, Y Taki3, Y Kotozaki4, R Nouchi4,5, H Takeuchi4, T Araki4, S Hanawa1, S Nakagawa1, C M Miyauchi1, A Sakuma1,6 and R Kawashima1,3,4
- 1Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
- 2International Research Institute of Disaster Science, Tohoku University, Sendai, Japan
- 3Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
- 4Smart Ageing International Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
- 5Japanese Society for the Promotion of Science, Tokyo, Japan
- 6Department of Psychiatry, Tohoku University Graduate School of Medicine, Sendai, Japan
Correspondence: Dr A Sekiguchi, Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. E-mail: firstname.lastname@example.org
Received 22 December 2011; Revised 4 April 2012; Accepted 9 April 2012
Advance online publication 22 May 2012
Advance online publication 22 May 2012
The Great East Japan Earthquake, a severe magnitude 9.0 earthquake, hit Japan on 11 March 2011. The eastern half of Japan was severely affected, and the northeast coast suffered widespread destruction caused by a massive tsunami triggered by this earthquake. More than 15 000 people have been confirmed dead, and ~4000 remain missing 6 months after the earthquake. Stress-related disorders such as acute stress disorder and posttraumatic stress disorder (PTSD) are likely to occur among the large number of survivors,1, 2, 3 but even those without PTSD will require psychological support.4 However, survivors without PTSD are likely to hesitate to ask for psychological supports and may not receive help, in contrast to those with PTSD. Distinguishing neurological abnormalities as a vulnerability factor from the acquired signs of PTSD symptoms in the early stage of adaptation to the trauma is essential both to understand the pathogenesis of PTSD and to prevent survivors from developing PTSD. Such information may provide a better understanding of posttraumatic responses and the development of effective methods to prevent PTSD.
The neurological underpinnings of PTSD have been well characterized, but the causal relationships to the traumatic event remain unclear, because of difficulties with prospective studies.5 Previous neuroimaging studies of patients with PTSD revealed morphological changes in several brain regions, including the hippocampus/parahippocampus,6 amygdala,6 anterior cingulate cortex (ACC),7, 8, 9 insula10 and orbitofrontal cortex (OFC),11, 12, 13 which were also found in healthy adults after stressful life events.14, 15 Evaluation of monozygotic twin pairs with combat-related PTSD has provided evidence that smaller hippocampal volume is a vulnerability factor for PTSD,16 and smaller pregenual ACC represents an acquired sign of PTSD.8 However, longitudinal structural changes as a vulnerability factor and an acquired sign of PTSD symptoms remain unclear. Some longitudinal studies have examined patients with PTSD after traumatic events, but failed to find subsequent brain structural changes.11, 17, 18 A recent longitudinal study revealed that decreased volumes in the ACC and hippocampus/parahippocampus were associated with the number of stressful life events, but the impacts of stress-related responses on brain structure were not examined.14 Therefore, the significance of longitudinal structural changes caused by posttraumatic response remained unclear.
This study tried to identify brain structural changes representing vulnerability factors and acquired signs of PTSD symptoms in non-PTSD survivors, based on a longitudinal study of structural magnetic resonance (MR) images obtained before and after the earthquake. In fact, we had obtained extensive structural MR imaging database from a group of healthy adolescents before the earthquake in multiple studies performed in our laboratory. Therefore, this extremely miserable episode provided a rare opportunity for investigating brain structural changes associated with such a disaster. We recruited 42 subjects from this group to examine structural MR images at 3–4 months after the earthquake. PTSD symptoms were also assessed using the Japanese version of the clinician-administered PTSD scale (CAPS) structural interview.19 We hypothesized that the vulnerability factors for PTSD could be detected by a significant association between the CAPS scores and smaller regional grey matter volume (rGMV) before the earthquake (Pre rGMV) in brain regions previously implicated in PTSD, and that the acquired signs could be detected by a significant association between the CAPS scores and decrease in rGMV from before to after the earthquake (Post-Pre rGMV). More specifically, based on previous monozygotic twin studies,8, 16 we could predict that smaller rGMV in the hippocampus would be identified as a pre-trauma vulnerability factor, and smaller rGMV in the ACC as an acquired sign of PTSD symptoms.