The CDC's biannual Youth Risk Behavior Surveillance Study is the largest and longest-running public health report monitoring high school students in the country. Here are five takeaways from this year's report.

1. Fewer teenagers are using illegal drugs

The CDC has been surveying illicit drugs use since the study started in 1991. The CDC has found a "significant linear decrease" in teenagers reporting having ever used drugs including inhalants, heroin, methamphetamine, ecstasy, hallucinogenic drugs.
The percentage of teenagers who reported using marijuana in the 30 days before the survey did not significantly change since 1991. However, the CDC has found that marijuana use increased from 1991 to 1995, then decreased from 1995 to 2017.

For the first time in the study's 27 year history, the survey asked if students had ever taken prescription pain medicine without a doctor's prescription or used medication differently than directed. Nationwide, 14 percent of students said they had. Ten percent of high school freshmen and 17 percent of seniors said that had taken prescription pain medicine outside of a doctor's prescription at least once.

2. Both cigarette smoking and vaping have declined dramatically

When the survey started in 1991, just over 70 percent of high schoolers said they had tried smoking cigarettes at least once. In 2017, that number was down to less than 29 percent.

Similarly, the percentage of students who smoke cigarettes regularly has decreased. From 1997 to 2017, the percentage of students who reported smoking within the 30 days before the survey decreased from just over 34 percent to under 9 percent.

The CDC began monitoring electronic vapor products in 2015. Around two out of every five high school students said they have tried electronic vaping at least once.

The percentage of students who said they have tried vaping has not significantly changed, but the CDC saw a that half as many students reported regularly using vaping products in 2017 compared to 2015.

3. More teens are waiting to become sexually active

When the CDC started the Youth Risk Behavior Survey in 1991, more than 54 percent of high schoolers said they had participated in sexual intercourse at some point. The CDC has found a significant linear decrease trend. In 2017 that number was just under 40 percent.

Almost 29 percent of students said they had intercourse in the three months before the survey.

Of those sexually active, 53.8 percent reported using a condom the last time they engaged in intercourse. Though that percentage is higher than what the survey first found in 1991, it is 9 percentage points lower than what the CDC found in 2005.

4. Many students report feeling sad or hopeless

More than 31 percent of high schoolers say they felt so sad or hopeless almost every day for at least two weeks to the point that they stopped doing some usual activities during at least one period in the 12 months before the survey.

The CDC has found a significant linear increase since it began collecting data on the category in 1999.

High schools girls are about twice as likely to say they felt sad or hopeless for an extended period than high school boys.

For the second time the CDC asked teenagers about their sexual orientation in order to distinguish challenges facing students related to that demographic.

Twenty-seven percent of heterosexual students reported feeling sad or hopeless. For students who identified as gay, lesbian or bisexual, 63 percent reported feeling sad or hopeless. For students who were not sure of their orientation, more than 46 percent report feeling sad or hopeless.

5. Suicide attempts have decreased but are disproportionately high among LGBT teens

Nationwide, 7.4 percent of students say they attempted suicide in the year before the study. The CDC says it has seen a significant linear decrease in the overall prevalence of attempted suicide.

Once again, the prevalence in this category was almost twice as high among girls as it is among boys, but the greater disparity is between heterosexual and homosexual students.

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