Concerned that your adolescent is watching too much TV? A new study gives parents good reason to be concerned. Researchers reported this week that greater exposure to TV during the teenage years appears to raise the risk of depression in young adulthood, especially among males.
Dr. Brian A. Primack, of the University of Pittsburgh School of Medicine and colleagues studied the media habits of roughly 4,100 healthy non-depressed adolescents. They asked the adolescents how many hours they spent during the last week watching TV or videos, playing computer games or listening to the radio.

The adolescents reported an average of 5.68 hours of media exposure each day, including 2.3 hours of TV viewing per day.

Seven years later (at an average age of 21.8), the study subjects were screened and 308 (7.4 percent) had developed symptoms of depression.

According to the report, published in the Archives of General Psychiatry, for each hour of TV viewed per day, the teens had a statistically significant greater likelihood of developing depression in young adulthood.

Given the same amount of media exposure, young women were less likely to develop symptoms of depression than were young men.

"We did not find a consistent relationship between development of depressive symptoms and exposure to videocassettes, computer games, or radio," they report.

There are several possible ways by which media exposure could boost the risk of depression, the researchers say. The time spent watching TV or using other electronic media may replace time spent socializing, participating in sports or engaging in intellectual activities — all of which may protect against depression.

Watching TV at night may disrupt sleep, which is important for normal brain and emotional development. In addition, messages transmitted through the media may reinforce aggression and other risky behaviors, interfere with identity development or inspire fear and anxiety, the researchers note.

This study, they conclude, "breaks new ground in linking media use in adolescence to the development of depressive symptoms in young adulthood."

担心你家的孩子看电视太多吗？一项新的研究给父母们提供了担心的充分理由。本周，研究者们在报告中说，青少年时期看电视过多能增加成年早期的抑郁风险，特别是在男性之中。

匹兹堡大学医学院的布莱恩A. 普里马克博士和同事们研究了大约4100名健康无抑郁症状青少年的媒体习惯。他们询问了这些青少年上周花了多少小时看电视或录像，玩电脑游戏或听收音机。

这些青少年的回答表明他们每天媒体暴露的时间平均为5.68小时，其中包括了每天2.3小时的看电视时间。

7年后（这些青少年的平均年龄为21.8岁），对这些研究对象进行了筛选，结果有308人（占7.4％）出现了抑郁的症状。

根据发表在《普通精神病学文献》上的报告，我们可以知道，每天每增加一小时看电视的时间，从统计学的意义上来说，这些青少年都有更大的可能在成年早期患抑郁症。

在给予相同的媒体暴露时间的情况下，年轻女性比年轻男性患抑郁症的可能要小。

“我们没有发现患抑郁症和接触录像、电脑游戏或收音机之间有同样的关联。”他们在报告中写到。

研究者们说，媒体暴露会通过几种可能的方式增加抑郁的风险。花在看电视或者使用其他电子媒体上的时间，可能取代花在参加社会活动、参加体育活动或从事智力活动上的时间——而这些活动都可以防止抑郁。

晚上看电视可以干扰睡眠，睡眠对于正常的大脑和情感的发育很重要。另外，通过媒体传递的信息可以强化攻击性和其他危险的行为，干扰个性发展或激发恐惧和焦虑情绪，研究者补充说。

他们总结说，这项研究“在把青少年的媒体使用情况和成年早期患抑郁症之间联起来方面开辟了新的领域。”