School of Psychiatry, University of New South Wales (UNSW), Randwick, NSW, Randwick, NSW, Australia.
Neuroscience Research Australia, Randwick, NSW, Australia.
Acta Psychiatr Scand. 2018 Oct;138(4):312-324. doi: 10.1111/acps.12920. Epub 2018 Jun 27.
Exposure to sexual assault is a significant risk factor to develop post-traumatic stress disorder (PTSD) in females. The early neurobiological changes leading to the development of PTSD remain understudied and unclear in this population.
Participants were 27 adult females recruited within a month following exposure to sexual assault (T1) and 20 age-matched non-exposed controls. Among the victims, 10 participants met (PTSD+) and 15 did not meet (PTSD-) DSM-IV criteria for PTSD 6 months post-trauma (T2). At both visits, hippocampal and amygdala volumes were extracted from magnetic resonance imaging scans, and indices of total diurnal cortisol changes were derived from individual areas under the curve relative to the ground (AUCg). Measures at T1 were compared between groups at T1, measures at T2 between groups at T2, and measures at T1 between groups at T2.
At T1, victims had significantly smaller bilateral hippocampal volumes, but not AUCg, than controls. At T2, neither hippocampal volume nor AUCg significantly differed among the groups. However, the PTSD+ group had significantly smaller hippocampal volumes at T1 than the control group, but not compared to the PTSD- group.
This study indicates that having smaller hippocampal volumes is a risk factor to develop PTSD in females exposed to sexual assault.
性侵犯暴露是女性发生创伤后应激障碍（PTSD）的一个重要风险因素。在该人群中，导致 PTSD 发展的早期神经生物学变化仍研究不足且不清楚。
参与者为 27 名在性侵犯后一个月内招募的成年女性（T1 期）和 20 名年龄匹配的未暴露对照者。在受害者中，有 10 名符合（PTSD+），15 名不符合（PTSD-）创伤后 6 个月（T2 期）DSM-IV PTSD 标准。在两次就诊时，从磁共振成像扫描中提取海马体和杏仁核体积，并从个体曲线下面积相对于基线（AUCg）中得出总日间皮质醇变化的指数。在 T1 期，将组间 T1 期的测量值进行比较，组间 T2 期的测量值进行比较，组间 T1 期的测量值进行比较。
在 T1 期，受害者的双侧海马体体积明显小于对照组，但 AUCg 无差异。在 T2 期，各组间海马体体积和 AUCg 均无显著差异。然而，PTSD+组在 T1 期的海马体体积明显小于对照组，但与 PTSD-组无差异。
本研究表明，海马体体积较小是女性遭受性侵犯后发生 PTSD 的一个风险因素。
