Lengthy television viewing in adolescence may raise the risk for depression in young adulthood, according to a new report.

The study, published in the February issue of The Archives of General Psychiatry, found a rising risk of depressive symptoms with increasing hours spent watching television.

There was no association of depression with exposure to computer games, videocassettes or radio.

Researchers used data from a larger analysis of 4,142 adolescents who were not depressed at the start of the study. After seven years of follow-up, more than 7 percent had symptoms of depression.

But while about 6 percent of those who watched less than three hours a day were depressed, more than 17 percent of those who watched more than nine hours a day had depressive symptoms.

The association was stronger in boys than in girls.

“We really don’t know what it was specifically about TV exposure that was associated with depression, whether it was a particular kind of programming or some contextual factor such as watching alone or with other people, said Dr.Brian Primack, the lead author and an assistant professor of medicine at the University of Pittsburgh.

NICHOLAS BAKALAR