Chan Stella W Y, Harmer Catherine J, Norbury Ray, O'Sullivan Ursula, Goodwin Guy M, Portella Maria J
Section of Clinical Psychology, School of Health in Social Science, University of Edinburgh, Edinburgh EH8 9AG, UK; University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK.
University Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK.
J Affect Disord. 2016 Jan 1;189:199-202. doi: 10.1016/j.jad.2015.09.021. Epub 2015 Oct 1.
Reduced hippocampal volume has been associated with clinical depression. However, it remains unclear whether these changes are a biological vulnerability marker or a consequence of this disorder. METHODS AND RESULTS (STUDY 1): We first compared hippocampal volumes between (i) never-depressed individuals with elevated risk for depression by virtue of high neuroticism (ii) recovered depressed individuals with matched levels of neuroticism; and (iii) individuals with low neuroticism and no history of depression. We replicated the finding of reduced hippocampal volume in the recovered group; unexpectedly however, the never-depressed high-risk group showed an increase in volume. One hypothesis is that this group had a mean age above the typical onset age for depression; hence, these participants who have remained euthymic despite their personality risk might in fact possess some resilience. METHODS AND RESULTS (STUDY 2): A subsequent study was therefore carried out to compare hippocampal volume between high-neurotic vs. low-neurotic volunteers in a younger sample. No group difference was found.
The present findings are limited by a small sample size; the cross-sectional design precluded us from makineg definitive conclusions about causal effect.
Our overall results suggest that reduced hippocampal volumes is a neural marker for the scar effect of depression, although this structural impairment could also be seen as a vulnerability marker for the development of future recurrent episodes. By contrast, larger hippocampal volumes could be a biological marker of resilience. These findings have clinical implications regarding treatment development for the prevention of illness onset and recurrent depressive episodes.
海马体体积减小与临床抑郁症有关。然而，这些变化是生物学易感性标志物还是这种疾病的后果仍不清楚。
方法与结果（研究1）：我们首先比较了以下三组人群的海马体体积：（i）因高神经质而患抑郁症风险升高的从未患抑郁症个体；（ii）神经质水平匹配的康复抑郁症个体；以及（iii）低神经质且无抑郁症病史的个体。我们在康复组中重现了海马体体积减小的发现；然而，出乎意料的是，从未患抑郁症的高风险组体积增加。一种假设是，该组的平均年龄高于抑郁症的典型发病年龄；因此，尽管有性格风险但仍保持心境正常的这些参与者实际上可能具有一定的恢复力。
方法与结果（研究2）：因此，随后进行了一项研究，以比较较年轻样本中高神经质与低神经质志愿者的海马体体积。未发现组间差异。
本研究结果受样本量小的限制；横断面设计使我们无法就因果效应得出明确结论。
我们的总体结果表明，海马体体积减小是抑郁症瘢痕效应的神经标志物，尽管这种结构损伤也可被视为未来复发发作发展的易感性标志物。相比之下，较大的海马体体积可能是恢复力的生物学标志物。这些发现对预防疾病发作和复发性抑郁发作的治疗开发具有临床意义。
