An increasing number of South Korean youth suffer from depression and sleep disorders due to stress, with many of them going untreated, data showed Tuesday.

According to the data compiled by the National Health Insurance Corp. (NHIC), 23,806 adolescents aged 10 to 19 nationwide received treatment for depression last year, up 15.3 percent from 20,633 in 2006. During the five-year period, the sheer number of youth in that age group rose 1.1 percent.

The number of the country's youth who visited a medical clinic for sleep disorders -- both sleep deprivation and narcolepsy, an excessive urge to sleep at inappropriate times -- came to 3,232 last year, up 56.4 percent from the year 2006, the data showed.

"Sleep problems are one of the key indicators of the underlying disorder of depression," said Jun Tae-youn, the psychiatrist from Seoul St. Mary's Hospital. "So more children suffering from sleeping disorders means we could have more young depression patients down the road."

Stressful circumstances that adolescents face, such as fiercer competition, are taking an increasing toll on them, according to experts.

"Students these days are required to be outstanding in many different fields to make it to a prestigious college, which victimizes even preschool kids," Jun said.

In fact, a survey by state-run Statistics Korea last May found that more than 70 percent of 3,089 respondents aged 15 to 19 said they come under stress, up 13.1 percent from two years earlier.

Over half of them said studying and overall school life bothered them the most, followed by concerns about their looks, future occupations and family environments, it showed.

But many adolescent patients have gone untreated, posing greater threats to both their mental and physical health as well as society as a whole, according to the Seoul Child and Adolescents Mental Health Center.

"In Seoul alone, 4.6 percent of middle and high school students were advised to receive treatment for serious depression last year.

But we've learned from the NHIC data that less than 0.5 percent of them received treatment," an official from the Seoul center said.

"The disorder tends to occur easily in adolescents, but proper care leads to a full recovery. So the key is an early diagnosis and treatment, not to mention preventive measures such as counseling," he added. (Yonhap News)