Teens whose parents pack them off to bed at 10 p.m. are less apt to become depressed or have suicidal thoughts than their peers who stay up much later, recent research shows.

"This study bolsters the argument that a lack of sleep can cause depression," said study author James Gangwisch, an assistant professor of psychiatry at Columbia University Medical Center in New York City. "Teens with earlier parental-mandated bedtimes were less likely to suffer from depression and suicidal thoughts."

Gangwisch was to present the findings Tuesday at the Associated Professional Sleep Societies annual meeting, in Seattle.

The study stemmed from data on more than 15,000 adolescents who participated in the National Longitudinal Study of Adolescent Health.

The researchers found that 1,143 of the teens were depressed and 2,038 had suicidal ideation, the term clinicians use to describe suicidal thinking. Dr. Jonathan Pletcher, an adolescent medicine specialist from Children's Hospital of Pittsburgh, pointed out that suicidal thoughts are common in teenagers, which is why the study included more teens with suicidal thoughts than depressed adolescents.

"A lot of teens have suicidal thoughts, but there's a big difference between suicidal ideation and being suicidal," Pletcher said.

When Gangwisch and his research team looked at the relationship of depression and suicidal thoughts to parental-mandated bedtimes, they found a clear correlation.

Teens whose parents insist on 10 p.m. or sooner for lights out were 25 percent less likely to be depressed and 20 percent less likely to have suicidal thoughts, compared with kids who hit the sack at midnight or later.

Gangwisch said he adjusted the data to account for numerous factors, including parental connectedness and the age of the teens, because older teens probably would have later bedtimes. After controlling for these factors, he said, it was clear that a lack of sleep was to blame for the increased risk of depression and suicidal thoughts.

"Kids that have to go to bed earlier are getting more sleep," he said.

Pletcher said it's likely that a combination of factors accounted for the increased risk. "There's a bi-directional relationship between depression and sleep," he said. "Teens who get less sleep may be more anxious and more likely to feel badly. But, I think this study's findings also speak to a connection between the teen and their parents and their ability to work together."

Both Gangwisch and Pletcher agreed that most teens need at least eight to nine hours of sleep a night, and said that parents might underestimate their teen's need for sleep.

"Getting adequate sleep is a huge priority," said Pletcher. Besides increasing the risk for depression and suicidal thoughts, a lack of sleep can affect a child's focus and learning, he said. And Gangwisch said that a dearth of sleep is also associated with obesity and type 2 diabetes.

Pletcher said that teens who don't get enough sleep may also be more impulsive.

"Don't underestimate how a lack of adequate sleep can affect everything from mood to behavior," he advised.

最近的研究表明，父母们在晚上10点钟就打发睡觉的年轻人们和他们的同龄人相比，较不易于有抑郁或自杀想法的倾向。

"此研究支持睡眠缺乏会导致抑郁症的争论，"此研究的作者纽约市哥伦比亚大学医学中心的精神病助理教授James Gangwisch说道。"那些有父母规定的较早的睡眠时间的年轻人较不易于遭受抑郁症和自杀的想法。"

Gangwisch将于本周二在西雅图市举办的联合职业睡眠社会年度会议上提出此研究的各项发现。

此研究的数据源自于参加了国家青少年健康纵向研究的15,000多名青年。

研究人员发现，这些年轻人中有1,143名有抑郁症，而2,038名有自杀的构想，临床医生用这个词组描述自杀的想法。匹兹堡儿童医院的青少年药物专家Jonathan Pletcher博士指出，自杀构想在年轻人中十分普遍，这就是为何此研究中涉及的有自杀想法的年轻人多于抑郁症的年轻人。

"很多年轻人都有自杀的想法，但是在自杀的想法和实施自杀之间有很大的不同。"Pletcher说道。

Gangwisch及其研究队伍查看抑郁症，自杀构想和父母规定的睡眠时间的关系时，他们发现了一个明确的关联。

与那些在午夜或更晚入睡的年轻人相比，那些父母坚持在晚上10点或更早熄灯的年轻人们患抑郁症的几率降低25%,而有自杀构想降低了20%.

Gangwisch说，他调整了数据来证明许多因素，包括与父母相关的因素，年轻人的年龄，因为较大的年轻人通常睡的更晚。在控制了这些因素后，他说，很明显，睡眠的缺乏应当对抑郁症和自杀构想增长的风险负责。

Pletcher说，多种因素的综合导致了增长的风险。"抑郁症和睡眠之间存在着双向关系，那些睡眠较少的年轻人可能更加焦虑和感觉糟糕。但是，我认为，此研究的发现也提及了青年和父母之间的关系，以及他们互相配合的能力。"

Gangwisch 和Pletcher都认为，多数青年需要每晚8到9小时的睡眠，而父母们可能低估了他们的孩子对于睡眠的需要。

"得到适当的睡眠是个巨大的优势，"Pletcher说道。除了增加抑郁症和自杀想法的风险，缺乏睡眠也能影响孩子的注意力和学习力。Gangwisch说，缺乏睡眠也和肥胖症以及二类糖尿病有关系。Pletcher说没有得到足够睡眠的青年人可能会更加冲动。"不要低估睡眠缺乏对从情绪到行为的影响。"他建议道。