美国研究人员发现，压力致使大脑萎缩，可能影响大脑功能，增加罹患高血压等慢性病以及精神紊乱风险。
实际上，不少人知道压力可能引发头疼和夜间失眠。
询压力
耶鲁大学神经生物学家拉吉塔·辛哈和同事征募103名成年人。志愿者年龄为18岁至48岁，身体健康。
借助结构式访谈，研究人员收集志愿者应激性生活事件的信息，包括丧失亲人、经济窘迫、失业等，了解志愿者对慢性压力的主观感受。
美国微软—全国广播网（MSNBC）援引辛哈的话报道，这里所指压力并非时间期限迫近、错过公交车这类普通压力，而是指“坏事情，譬如恋爱关系破裂、失去挚爱、被枪指着等”。
致萎缩
随后，研究人员借助功能性磁共振成像技术（MRI）扫描志愿者的大脑。结果显示，压力与大脑灰质萎缩存在关联。
辛哈在由美国《生物精神病学》网络版本周发表的研究报告中写道，仅仅主观上感觉压力大、不堪重负并不会引起大脑灰质萎缩，但不堪重负感加上应激性生活事件就会产生这种效果，尤其是大脑前额叶皮质层中灰质显著减少。前额叶皮质负责调节情绪和自我控制。
辛哈说，这种萎缩可能是一面小红旗，意味着罹患高血压等慢性病和精神紊乱风险增加；而且，压力可能正在影响研究中健康志愿者的大脑功能。
研究人员认为，现代生活压力远比先前所知复杂。
辛哈说，“你可以说压力是生活的一部分，不算什么大事”，但它就是一件大事，因为大量证据显示，压力是慢性病患者人数增加的推手。
巧减压
研究人员说，先前关于压力对大脑结构的影响这类研究，多数关注与压力相关的精神紊乱病患，譬如成瘾和焦虑，结果显示大脑额叶这个情绪控制和个性中心体积减小；但关注压力对健康人群大脑累积效应的研究相当少。
压力之下，男性还是女性的大脑萎缩更多？研究人员现阶段并不清楚，因为参与研究的志愿者中女性人数过少，不足以对比。
辛哈说，如果能够更好地应对压力，譬如散散步、给朋友打电话，大脑状况会更好。(生物谷 Bioon.com)
doi:10.1016/j.biopsych.2011.11.022
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Cumulative Adversity and Smaller Gray Matter Volume in Medial Prefrontal, Anterior Cingulate, and Insula Regions
Emily B. Ansell, Kenneth Rando, Keri Tuit, Joseph Guarnaccia, Rajita Sinha
Background
Cumulative adversity and stress are associated with risk of psychiatric disorders. While basic science studies show repeated and chronic stress effects on prefrontal and limbic neurons, human studies examining cumulative stress and effects on brain morphology are rare. Thus, we assessed whether cumulative adversity is associated with differences in gray matter volume, particularly in regions regulating emotion, self-control, and top-down processing in a community sample.
Methods
One hundred three healthy community participants, aged 18 to 48 and 68% male, completed interview assessment of cumulative adversity and a structural magnetic resonance imaging protocol. Whole-brain voxel-based-morphometry analysis was performed adjusting for age, gender, and total intracranial volume.
Results
Cumulative adversity was associated with smaller volume in medial prefrontal cortex (PFC), insular cortex, and subgenual anterior cingulate regions (familywise error corrected, p < .001). Recent stressful life events were associated with smaller volume in two clusters: the medial PFC and the right insula. Life trauma was associated with smaller volume in the medial PFC, anterior cingulate, and subgenual regions. The interaction of greater subjective chronic stress and greater cumulative life events was associated with smaller volume in the orbitofrontal cortex, insula, and anterior and subgenual cingulate regions.
Conclusions
Current results demonstrate that increasing cumulative exposure to adverse life events is associated with smaller gray matter volume in key prefrontal and limbic regions involved in stress, emotion and reward regulation, and impulse control. These differences found in community participants may serve to mediate vulnerability to depression, addiction, and other stress-related psychopathology.
