(AP) -- Gay and bisexual high school students are more likely than their heterosexual classmates to smoke, drink alcohol or do other risky things, according to a government study released Monday.
Based on anonymous surveys of 156,000 high school students, the Centers for Disease Control and Prevention study is the largest by the government to look at sexual orientation and behavior in teens. It echoes similar findings in some smaller studies.
Investigators asked about dozens of risky behaviors, ranging from not wearing a bicycle helmet, to drug use, to attempting suicide. Gay, lesbian and bisexual students reported worse behavior in half to 90 percent of the risk categories, depending on the survey site.
Why? CDC officials don't know for sure: The survey didn't ask kids why they smoked or attempted suicide or did other things that could be dangerous.
But gay, lesbian and bisexual students deal with stigma, disapproval and social rejection. "Many risk behaviors are related to how people feel about themselves and the environment they're in," noted the study's lead author, Laura Kann of the CDC's division of adolescent and school health.
The surveys are from 2001 through 2009. Some results, which vary by survey site:
-About 8 percent to 19 percent of heterosexual students said they currently smoke cigarettes; 20 percent to 48 percent of gay and lesbian students smoked.
-About 4 to 10 percent of heterosexual students said they attempted suicide in the previous year. For gay and lesbian students: 15 percent to 34 percent. For bisexual students: 21 percent to 32 percent.
-About 3 percent to 6 percent of heterosexual students said they threw up or used laxatives to lose weight or stay thin. For gay and lesbian students: 13 percent to 20 percent. For bisexual students: 12 percent to 17.5 percent.
The core results came from surveys done in five states and four city school systems. The states were Delaware, Maine, Massachusetts, Rhode Island and Vermont. Boston, Chicago, New York City and San Francisco rounded out the list.
The results are not considered nationally representative, but the research is larger and more geographically diverse than past studies. Kann presented the findings at a first-ever Department of Education summit for lesbian, gay and bisexual youth in Washington.
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More information: CDC report: http://www.cdc.gov/HealthyYouth/yrbs/index.htm