春天自殺率陡增 都是太陽惹的禍!

Over the next few months in the northern hemisphere, suicides are likely to become more common. Why?

在北半球接下來的幾個月裏，自殺現象可能會更加普遍，這是爲什麼呢？

Studies dating back to the 1800s have found that suicides peak in the spring and are lowest in winter.

19世紀的研究發現，自殺率在春季達到頂峯，在冬季最低。

"If we take winter as a baseline, then there's a 20-60% higher suicide rate during spring," says Fotis Papadopoulos, a professor of psychiatry at Uppsala University in Sweden, who has been studying the association.

瑞典烏普薩拉大學精神病學教授福蒂斯·帕帕多普洛斯表示：“如果我們以冬季的自殺率爲基準，那麼春季的自殺率將高出20-60％。”

This seems rather counterintuitive considering that darker days are linked to low mood. How could this be?

這似乎是相當違反我們的認知的，我們通常認爲萎靡的心情與較暗的天氣有關。那這到底是怎麼一回事呢？

One possibility is that this is a result of changing levels of serotonin – a neurotransmitter that regulates mood – within the brain.

一個可能的原因就是，這是血清素水平升高的結果，即5-羥色胺（一種在大腦內調節心境的神經遞質）。

Studies have found that serotonin levels in the blood are higher during the summer than the winter, and that there's a positive correlation between serotonin synthesis and the hours of sunshine on the day that a blood sample is taken.

研究發現，夏季血液中5-羥色胺水平高於冬季，血清素合成與攝取當天陽光時間呈正相關。

There's also a further connection, in that selective serotonin reuptake inhibitor (SSRI) antidepressants, which boost serotonin, have been linked to risk of suicide in a small number of patients.

還有一個更進一步的聯繫：在選擇性5-羥色胺再攝取抑制劑（SSRI）抗抑鬱藥中，其促進5-羥色胺與少數患者的自殺風險相關。

"We know that when we treat patients with antidepressants it can take at least three or four weeks to raise their mood," says Papadopoulos. "During this time, some people become more physically active or agitated, which could potentially make them more likely to act on their thoughts. Maybe sunshine acts in a similar way in a minority of people."

帕帕多普洛斯說道：“我們知道，當我們用抗抑鬱藥治療患者時，可能需要至少三到四個星期來使他們恢復好心情。在這段時間裏，有些人變得更加活躍或激動，這可能會使他們更有可能採取行動。或許陽光對一部分人起到的是同樣的作用。”