Latino high school students use drugs and attempt suicide at higher rates than their black and white classmates, according to a new federal survey that shows the continuation of a disturbing trend.

The study is the latest in a series of surveys of high school students every two years. The new report found that black and white students are reporting less sexual activity than in years past, but there was no decline among Latinos.

In addition, Latino students were more likely than either blacks or whites to attempt suicide, ride with a driver who had been drinking alcohol, or use cocaine, heroin or ecstasy.

Latinos also most often drank alcohol on school property, were offered or sold illegal drugs, and occasionally skipped school because they feared for their safety, according to the 2007 survey by the Centers for Disease Control and Prevention.

Experts were unable to come up with an explanation for why Latino behavior trends differed. However, they speculated that school environments many Latinos face may differ considerably from what adolescents of other races encounter. Earlier research found that Latino and black students more commonly attend highly segregated schools than white or Asian students.

"There's tremendous segregation in our schools," said Howell Wechsler, director of adolescent and school health for the CDC.

He said he was very troubled that Latino teens had not improved in certain risk areas at the same rate as blacks and whites.

The finding comes from a survey of about 14,000 high school students that has been conducted every other year since 1991. Questionnaires go to students in grades 9-12 in public and private high schools in all 50 states and the District of Columbia.

Researchers got parental permission for each student who participated. The survey did not collect information on parent income or education. Some experts say those factors also can be a strong indicator of a youth's health behavior and academic achievement.

Adolescents cannot always be counted on to tell the truth about their sexual exploits, drug use or other risky behaviors. But CDC officials say they take many steps to secure accurate responses: Participation is confidential, kids are spaced apart when answering the questions and teachers do not hover.

The survey asks about a wide variety of behaviors, including sunscreen use, seat-belt avoidance, drug use and suicide attempts.

Among other findings, the study noted that the proportion of students who said they recently smoked a cigarette was the same as the proportion who recently used marijuana - 20 percent.

Like the 2005 survey, the 2007 data showed higher rates of risk-taking by Latinos in several areas.

One example: About 10 to 11 percent of Latino students said they attempted suicide, compared with around 7 percent of whites and 8 percent of blacks.

However, whites reported the highest rates of smoking and heavy drinking, while blacks reported the highest rates of obesity, violence and sexual activity.

One striking behavior in which black students fared the worst was television watching.

The American Academy of Pediatrics recommends no more than two hours of daily TV viewing a day for kids. Physical activity is needed to develop mental and social skills and help prevent obesity, and TV violence has been associated with more aggressive behavior in children who watch a lot of it.

Overall, TV watching by high school students has been generally steady, with about 35 percent watching three or more hours a day.

But the new report shows that about 63 percent of black students watched three or more hours a day. In contrast, 43 percent of Latino students and 27 percent of whites watched too much TV, the report concluded.

"We don't see that kind of gap" in almost any other measurement of risky health behaviors, Wechsler said.