美國研究人員發(fā)現(xiàn)，壓力致使大腦萎縮，可能影響大腦功能，增加罹患高血壓等慢性病以及精神紊亂風(fēng)險(xiǎn),。
實(shí)際上，不少人知道壓力可能引發(fā)頭疼和夜間失眠,。
詢壓力
耶魯大學(xué)神經(jīng)生物學(xué)家拉吉塔·辛哈和同事征募103名成年人,。志愿者年齡為18歲至48歲，身體健康,。
借助結(jié)構(gòu)式訪談,，研究人員收集志愿者應(yīng)激性生活事件的信息，包括喪失親人,、經(jīng)濟(jì)窘迫、失業(yè)等,，了解志愿者對(duì)慢性壓力的主觀感受,。
美國微軟—全國廣播網(wǎng)（MSNBC）援引辛哈的話報(bào)道，這里所指壓力并非時(shí)間期限迫近,、錯(cuò)過公交車這類普通壓力,，而是指“壞事情，譬如戀愛關(guān)系破裂,、失去摯愛,、被槍指著等”。
致萎縮
隨后,，研究人員借助功能性磁共振成像技術(shù)（MRI）掃描志愿者的大腦,。結(jié)果顯示，壓力與大腦灰質(zhì)萎縮存在關(guān)聯(lián),。
辛哈在由美國《生物精神病學(xué)》網(wǎng)絡(luò)版本周發(fā)表的研究報(bào)告中寫道,，僅僅主觀上感覺壓力大、不堪重負(fù)并不會(huì)引起大腦灰質(zhì)萎縮,，但不堪重負(fù)感加上應(yīng)激性生活事件就會(huì)產(chǎn)生這種效果,，尤其是大腦前額葉皮質(zhì)層中灰質(zhì)顯著減少,。前額葉皮質(zhì)負(fù)責(zé)調(diào)節(jié)情緒和自我控制。
辛哈說,，這種萎縮可能是一面小紅旗,，意味著罹患高血壓等慢性病和精神紊亂風(fēng)險(xiǎn)增加；而且,，壓力可能正在影響研究中健康志愿者的大腦功能,。
研究人員認(rèn)為，現(xiàn)代生活壓力遠(yuǎn)比先前所知復(fù)雜,。
辛哈說,，“你可以說壓力是生活的一部分，不算什么大事”,，但它就是一件大事,，因?yàn)榇罅孔C據(jù)顯示，壓力是慢性病患者人數(shù)增加的推手,。
巧減壓
研究人員說,，先前關(guān)于壓力對(duì)大腦結(jié)構(gòu)的影響這類研究，多數(shù)關(guān)注與壓力相關(guān)的精神紊亂病患,，譬如成癮和焦慮,，結(jié)果顯示大腦額葉這個(gè)情緒控制和個(gè)性中心體積減小,；但關(guān)注壓力對(duì)健康人群大腦累積效應(yīng)的研究相當(dāng)少,。
壓力之下，男性還是女性的大腦萎縮更多,？研究人員現(xiàn)階段并不清楚,，因?yàn)閰⑴c研究的志愿者中女性人數(shù)過少，不足以對(duì)比,。
辛哈說,，如果能夠更好地應(yīng)對(duì)壓力，譬如散散步,、給朋友打電話,，大腦狀況會(huì)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.
