NEW YORK (Reuters Health) – Eating disorder symptoms are only temporary for many adolescents, according to the results of a self-reported survey conducted in Finland. However, among teens with persistent or recurring symptoms, anxiety appears to be an underlying factor.

Teens who don't get better on their own usually have many other mental and physical problems, the study demonstrates.

"However, our findings should not be interpreted as meaning that 'wait and see' would be an adequate approach with adolescents who report eating disorder symptoms but no other problems," Lea Hautala, a PhD student at the University of Turko, and her colleagues warn in their report in the Journal of Advanced Nursing.

In Western cultures, Hautala and her colleagues note, disordered eating is relatively common among adolescents. Eating disorder symptoms will last for one to two years in 50 percent to 60 percent of teens, while just one in 10 adolescents with eating disorder symptoms will develop an eating disorder that persists into adulthood.

The researchers followed 372 boys and girls 15 to 17 years old for one year to determine whether certain factors could help identify individuals who would have more long-lasting eating problems. A survey was administered at study entry and again one year later.

At the initial assessment, 13 percent of the study participants reported having some eating disorder symptoms on the first or second survey, while five percent reported symptoms on both surveys.

While five times as many girls as boys had persistent eating disorder symptoms, the proportion of boys who had the symptoms at just one point in time was larger, with just twice as many girls as boys.

The students who reported eating disorder symptoms at both time points were more likely than their peers to also have several other psychological and health problems.

But anxiety was the only factor that independently predicted the risk of persistent eating disorder symptoms; individuals with eating disorder symptoms who were identified as anxious at the study's outset were 20 times more likely to still have those symptoms a year later.

"Our findings suggest that disordered eating does not occur separately, but as part of a more extensive ill-being," Hautala and her team say.

"Therefore, adolescents who have psychological problems or multiple health complaints should be screened for eating disorder symptoms."