SHANGHAI, June 7(AP) -- A 16-year-old girl's suicide after she was barred from a key exam underscores mounting worries over academic pressures, as millions of Chinese students began annual college entrance tests on Wednesday.

The three-day exam, viewed as crucial to future career and financial success, has a record 9.5 million high school students across China competing for just 2.6 million university places. For kids and parents alike, it's a nail-biting ordeal that experts say causes undue emotional distress.

"Pressure from study and exams is a top reason for psychological problems among Chinese youth," said Jin Wuguan, director of the Youth Psychological Counseling Center at Shanghai's Ruijin Hospital.

In China's increasingly success oriented, pressure-cooker cities, academic stress is seen as a rising cause of youth suicides and even murders of parents by children unhinged by overwhelming pressure to perform.

According to her family and newspaper accounts, 16-year-old Wu Wenwen drowned herself after she was stopped at the exam room door because her hair wasn't tied back as her school required.

Returning in barrettes, she was then told the end-of-term exam had already started and she was too late to take it. In tears, Wu called her mother, and then disappeared. Her body was found the same night in a nearby lake.

China doesn't keep comprehensive statistics on student suicides, but Jin said health care professionals see the problem worsening, even among elementary students.

Most Chinese schools still lack counselors and teachers receive little training in spotting symptoms of emotional distress, Jin said. Parents are little help, often piling on pressure while ignoring their children's emotional development, he said.

"It's a basic unwillingness or inability to recognize and deal with with emotional problems," Jin said.

Wang Yufeng, of Peking University's Institute of Mental, estimates the rate of emotional disorders such as depression and paranoia among Chinese students under age 17 at up to 32 percent _ a total of 30 million students.

Others say that figure may be as high as 50 percent. A survey last year by the government's China Youth and Children Research Center showed 57.6 percent of students felt highly distressed by academic pressures.