Fewer high school students are having sex than ever before, federal health officials reported Thursday. And they’re also less likely than some earlier generations to abuse drugs, the Centers for Disease Control and Prevention’s annual survey on teen behavior finds.

But kids report that bullying at school is common and a third of students report persistent feelings of sadness and hopelessness, the report finds. One in 10 girls and one out of 28 boys report they’ve been forced to have sex.

“Today’s youth are making better decisions about their health than just a decade ago,” said Dr. Jonathan Mermin, who directs CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention.

“But, some experiences, such as physical and sexual violence, are outside their control and continue at painfully high levels. Their experiences today have powerful implications for their lives tomorrow.”

Every year, the CDC interviews several thousand students, choosing them to provide a nationally representative sample. The CDC cannot check whether the answers are accurate, but says the data these questionnaires generate is as acceptable as any self-reported data can be.

Condom use declining

In 2017, just 39.5 percent of the teenagers surveyed said they had ever had sex, down from 47.8 percent in 2007 and 57 percent in 1988.

Just under 10 percent said they had four or more sexual partners — something that puts people at higher risk of sexually transmitted infections such as HIV and gonorrhea. That compares to nearly 15 percent in 2007.

But barely over half had used a condom the last time they had sex, the survey found. That’s down significantly from 61 percent 10 years ago. Condoms are the only way to protect against most sexually transmitted diseases (STDs) such as gonorrhea and also protect against pregnancy and HIV.

“Half of the nearly 20 million new STDs reported each year are among young people aged 15-24,” the CDC notes in the report.

There was also a big drop in the number of kids using illicit drugs. In 2007, 22.6 percent of the students surveyed said they had used one or more illicit drug. This fell to 14 percent in 2017.

And fewer were injecting drugs — the most dangerous drug use behavior of all. “In 2017, 1.5 percent of high school students had ever injected any illegal drug into their body using a needle,” the report reads.

But the number of students who said they had been bullied stayed about the same — 19 percent in 2017, compared to 19.9 percent in 2009. And the same percentage overall say they had been forced into sex at some point — more than 7 percent. That included 11 percent of girls and 3.5 percent of boys.

And the number of these teens who say they have had persistent feelings of sadness or hopelessness rose from 28.5 percent in 2007 to 31.5 percent in 2017. More said they had seriously considered suicide —17 percent in 2017 compared to 14.5 percent in 2007.

“A significantly higher percentage of Hispanic students (33.7 percent) experienced persistent feelings of sadness or hopelessness than white students (30.2 percent) or black students (29.2 percent),” the report reads.

And more students were making suicide plans, as well, taking thoughts of suicide a step further.

“The percentage of female students who made a suicide plan increased significantly from 2007 (13.4 percent) through 2017 (17.1 percent),” the report read.

“The percentage of male students who made a suicide plan did not change significantly.” Just around 9 percent of male students said they had made a suicide plan. And 9 percent of girls actually attempted suicide, compared to 5 percent of boys.

Other reports have also found that more teens are attempting suicide.

It’s not clear why, but experts say both social media and a growing lack of connectedness in American society may be playing a role.