Death rates from drug overdoses among older teens grew in 2015 as a result of the opioid epidemic, according to a report released Wednesday by the Centers for Disease Control and Prevention.

Drug overdoses killed 772 people ages 15 to 19 in 2015, an increase from 658 deaths in 2014. Roughly 80 percent of the deaths were not intentional, and the rise was driven by overdoses from heroin. Nearly 14 percent of deaths from drug overdoses were suicides, and females were twice as likely than males to die by a drug overdose-related suicide.

The overdose death rate rose to 3.7 per 100,000 teens in 2015, from 3.1 the previous year. Much of the concentration was among males, who comprise two-thirds of drug overdose deaths.

The total number of deaths in 2015 was lower than in some years, though its rates were higher. For instance, in 2009, 797 young people died from a drug overdose, a rate of 3.6 per 100,000 teens.

CDC scientists cautioned that part of the growth rate may be attributable to rate changes as well as better reporting of which drugs are causing deaths. In 2000, for instance, 73 percent of drug overdose deaths listed the specific drug that led to the overdose. In 2015, 85 percent of overdose deaths specified the drug.

The rise in 2015 bucks years of decline, which parallel similar trends in teen drug, alcohol and tobacco use, as well as sexual activity.

Rates from drug overdose death had tripled from 331 in 1999 to a peak of 929 in both 2007 and 2008. The number of deaths and its rates were generally stable until 2011, and declined from 2012 to 2014.

These trends were markedly different from older age groups, in which tens of thousands have died. In 2015, 33,000 people died from a drug overdose, and among larger age groups the increase largely continued since 1999, rather than show the same decline that occurred among teens.