People who sleep with the lights on are more at risk of depression because the brightness can cause poor sleep quality and disrupt the "biological clock," a multiyear study showed.

一项多年的研究显示，睡觉开着灯的人更容易患抑郁症，因为亮度会使睡眠质量变差，扰乱“生物钟”。

A research team of the Nara Medical University said such disturbances¹ in body rhythm can lead to mental disorders², such as depression.

奈良医科大学的一个研究团队称，这种对身体节奏的干扰可导致精神障碍，例如抑郁症。

The team conducted the study on 863 men and women aged 60 or older from areas that included Asuka and Kashiba in Nara Prefecture.

这个团队对863名年龄在60岁及以上、来自包括飞鸟和香芝在内的奈良县各个地区的男男女女进行了研究。

The team set up sensors³ in the bedrooms of the 863 subjects between 2010 and 2014 to measure the light intensity⁴ from the time when they tucked into their beds or futon to the time they woke up.

该团队在2010年至2014年期间，在这863人的卧室里安装了传感器，测量从他们上床睡觉到睡醒这段时间内的灯光强度。

The subjects were each monitored for about two years for follow-up surveys regarding symptoms of depression.

为了关于抑郁症症状的跟踪调查，这些人被监测了约两年的时间。

According to the results, symptoms of depression were found in 52, or around 7.3 percent, of the 710 participants who slept in relative darkness with a median light intensity of just 0.4 lux.

结果显示，在相对黑暗的环境中（灯光平均亮度仅为0.4勒克斯）睡觉的710名参与者中，其中52人，也就是约7.3%，被发现有抑郁症症状，

Among the 153 participants who were exposed to brighter light with median intensity of 12.4 lux, 21, or 13.7 percent, showed such symptoms.

而在更明亮的环境中（平均强度为12.4勒克斯）睡觉的153名参与者中，则有21人，也就是13.7%，有此类症状。