CHICAGO (Reuters) — Talking obsessively about boys or the social pecking order may be considered a teen girl's rite of passage, but too much shared angst may be a bad thing, US researchers said this week.They said friendships that lend themselves to ruminating about problems may actually add to girls' emotional troubles.

"Talking about problems doesn't always make us feel better," said Amanda Rose of the University of Missouri, whose study appears in the journal Developmental Psychology.

Rose and colleagues found that adolescent girls who endlessly rehash their troubles may become overly anxious and even depressed.

One scenario — a teen boy dumps his girlfriend and asks another girl out. The spurned girl text-messages her best friend. They talk about it all during lunch, then on the cell phone in the afternoon and all evening.

They speculate for days about why the boy finds the other girl attractive and talk at length about how sad the jilted one feels.

"These girls have moved into a pattern of talking about problems that exacerbates their negative feelings," Rose said in a telephone interview. "It can get to be too much of a good thing."

For the six-month study, the researchers followed 813 girls and boys aged eight to 15.

What they found was ruminating together over problems boosted feelings of closeness and strengthened friendships for both boys and girls, but only girls experienced more anxiety and depression as a result of these talks.

The reason may be that the girls tended to believe they were personally responsible for their failures, Rose said.

As they become sad and anxious, this offers new fodder for future talks. "Clearly, this is a vicious cycle for girls, and it is likely one that will be difficult to stop," the researchers wrote.

But the news is not all good for boys, either.

"It is a real trade-off. It is positive that boys aren't at risk of depression and anxiety, but they also miss out on these increased feelings of connection with friends," Rose said. That's because boys ruminate with their friends less, she said.

Many studies have identified socially isolated children as being at risk, but Rose said parents should be aware that their girls' excessive gabfests may also pose a risk.

"If you encourage girls to dial it back a few notches, they would still feel the connection, but they may also have the opportunity to do other things together," she said.