This is the VOA Special English Health Report.

A new study suggests that the more teenagers watch television, the more likely they are to develop depression as young adults. But the extent to which TV may or may not be to blame is a question that the study leaves unanswered.

The researchers used a national long-term of adolescent health to investigate the relationship between media use and depression. They based their findings on more than four thousand adolescents who were not depressed when the survey began in nineteen ninety-five.

As part of the survey, the young people were asked how many of television or videos they watched daily. They were also asked how often they played computer and listened to the radio.

Media use totaled an average of five and one-half hours a day. More than two hours of that was spent watching TV.

Seven years later, in two thousand two, more than seven percent of the young people had signs of depression. The average at that time was twenty-one.

Brian Primack at the University of Pittsburgh medical school was the lead author of the new study. He says every hour of television meant an eight percent increase in the chances of developing signs of depression.

The researchers say they did not find any such relationship with the use of other media such as movies, video games or radio. But the study did find that young men were more likely than young women to develop depression given the same of media use.

Doctor Primack says the study did not explore if watching TV depression. But one possibility, he says, is that it may take time away from activities that could help prevent depression, like and socializing. It might also interfere with , he says, and that could have an influence.

The study was just published in the Archives of General Psychiatry.

In December, the journal Social Indicators Research published a study of activities that help lead to happy . Sociologists from the University of Maryland found that people who describe themselves as happy spend less time watching television than unhappy people. The study found that happy people are more likely to be active, to read, attend religious services and to vote.

And that's the VOA Special English Health Report, written by Caty Weaver. For archives of our reports, go to voaspecialenglish.com.