If life expectancy gives us “a snapshot of the nation’s overall health,” then new federal numbers released Thursday “are a wakeup call that we are losing too many Americans, too early and too often, to conditions that are preventable,” says Robert Redfield, the director of the Centers for Disease Control and Prevention.

According to the government’s annual mortality report, life expectancy in the U.S. overall fell in 2017 for the second time in three years.

The average American could expect to live 78.6 years, down from 78.7 years in 2016, according to the report from the National Center for Health Statistics.

The average American could expect to live 78.6 years, down from 78.7 years in 2016.

This is the first time since the Influenza Pandemic of 1918 that the U.S. has reported such a trend in lost life, said Robert Anderson, chief of mortality statistics with the National Center for Health Statistics.

The dip in 2017 is subtler than after the pandemic at the end of World War I (in that case, “we’re talking years of life expectancy, not tenths of years” like today), and doesn’t come from a single global infectious disease (although deadly flu cases did surge in 2017).

But Anderson said the latest data suggest this mortality trend is heavily influenced by the ongoing drug epidemic and a rising rate of suicides nationwide. And many people dying as a result of those two causes tend to be younger than in recent decades, he said.

“When young people die, it tends to be much more poignant,” Anderson said, noting the loss of so much unrealized human potential.

The National Center for Health Statistics made a few methodological changes to how they analyze their data, so 2016, a year that had previously been reported as a dip, now reads as flat.

Here are some key takeaways from the report.

Heart disease and cancer still drive U.S. deaths

Of the 2.8 million U.S. deaths recorded in 2017, heart disease and cancer continue to be the primary causes, accounting for a combined 44 percent of deaths overall, roughly the same as the previous year.

These deaths do not tend to influence the nation’s overall life expectancy as much, Anderson explained, because they typically occur later in life.

More than 70,000 people died as a result of drug overdose

Nationwide, 70,237 people died following a drug overdose in 2017, a 9.6-percent increase over 2016, when there were 63,600 fatal drug overdoses, according to federal data. The rate of 2017 deaths linked to drug overdose was 21.7 per 100,000 deaths — a startling rise from 1999, when the rate was 6.1 per 100,000 deaths.

In a supplementary report comparing trends in drug overdose deaths from 1999 to 2017, the highest rates of drug overdose deaths were found among adults between ages 25 and 54, the report said. These years tend to be those when people hit their peaks personally and professionally — forging new careers, forming romantic partnerships, having children and achieving that “potential.”

Nationwide, 70,237 people died following a drug overdose in 2017, a 9.6-percent increase over 2016.

West Virginia’s overdose death rate was more than double that of the national rate. Ohio and Pennsylvania had the next highest rates of overdose death. Nebraska, South Dakota and North Dakota reported the lowest rates of drug overdose deaths in the U.S.

In 2017, the greatest number of deadly overdoses were again from the use of opioids, totaling 47,600 deaths. Compared to almost 20 years ago, that rate increased five-fold, up from 2.9 per 100,000 deaths in 1999 to 14.9 per 100,000 deaths in 2017.

Breaking it down even further, nearly 28,500 people died after overdosing on synthetic opioids; the extremely potent drug fentanyl primarily drove those deaths. Heroin overdoses made up more than 15,400 deaths, marking a dramatic rise from 1999, when fewer than 2,000 people died from heroin overdose.

Suicide is on the rise

Last year, 47,173 Americans killed themselves, the latest federal data shows, marking a 3.7 percent increase from the previous year. More dramatically, suicide rates have risen 33 percent nationwide since 1999, from 10.5 to 14.5 per 100,000 deaths, with significant discrepancies between genders and among different communities.

The number of suicides in the U.S. “almost certainly is an undercount.”

Men were more than three times more likely to kill themselves than women, but the suicide rate among women is on the rise. Geographically, the overall number of suicides was greater in urban parts of the country, where the 2017 rate was 11.1 per 100,000 deaths, compared to 9.6 in 1999.

Although the total number of deaths in rural communities was smaller, the rate rose sharply during the same time period, up from 13.1 to 20 per 100,000 deaths.

Because so many drug overdose deaths are ruled as unintentional because of a lack of irrefutable evidence to suggest otherwise — such as a suicide note — Anderson said the number of suicides in the U.S. “almost certainly is an undercount,” but does not know to what extent.

Huge spike in flu-related deaths in 2017

In an echo of 1918, 2017 marked an historic rise in deaths linked to influenza and pneumonia, accounting for 5.9 percent of U.S. deaths overall and the ninth leading cause of death nationwide.

After the 2017 winter holidays, fatal flu and pneumonia cases began to tick upward, Anderson said. At this point in the current flu season, he said it is too soon to know if the U.S. will endure a similarly devastating flu season.

What has been done to address the deadly opioid crisis?

In 2017, President Donald Trump said his administration would work to bend the curve on opioid overdose deaths.

He declared opioid misuse and fatalities a public health emergency in October of that year, and in November, a commission Trump had established by executive order released 56 recommendations to curb the crisis.

Among those suggestions, the commission’s report suggested sharing data between the nationwide prescription drug monitoring program and the Department of Justice; greater federal coordination in all strategies targeting the opioid crisis; continuous training for anyone in the medical field who has authority to prescribe opioids; and more resources for opioid addiction treatment, overdose reversal and recovery.

“Another year of increasing numbers of drug overdose deaths is a national emergency, that can’t be overstated.”

But have those efforts made a dent in the 2018 number of fatal drug overdoses? Anderson said it is too early to know for certain, but with the first three months of 2018 data in hand, he said preliminary numbers “may indicate the drug overdose epidemic is leveling off.”

The scale and scope of people struggling with substance use and suicide attempts demands comprehensive action from government and health care sectors, said John Auerbach, president and chief executive officer of the Trust for America’s Health, in a released statement.

His organization, along with the Well Being Trust, released a 2017 report that projected as many as 1.6 million Americans may die in the decade leading up to 2025 from causes tied to alcohol, substance use and suicide if current trends persist. The report encouraged the adoption of a national resilience strategy, intended to boost supports, identify early warning signs and enhance treatment for people struggling with mental health and substance use.

“Another year of increasing numbers of drug overdose deaths is a national emergency, that can’t be overstated,” he said.

Beth Connolly, director for substance use prevention and treatment initiative at Pew Charitable Trusts and former commissioner for the New Jersey Department of Human Services, said, “more action is needed to address the opioid crisis.” High on her list: giving individuals access to medication-assisted treatment, “which has been proven to reduce opioid overdose deaths and save lives.”

Michael Botticelli, former drug czar during the Obama administration who now directs the Grayken Center for Addiction at Boston Medical Center, said that’s one of the actions — along with broader access to naloxone, an antidote that reverses the effects of an opioid overdose — we know are effective in fighting opioid addiction. Making sure that treatment is covered by insurance is just as important.

“There are states and localities that are bending the curve by implementing these and other strategies with urgency,” he said in a written statement to the PBS NewsHour. “Given the decrease in life expectancy, we need to focus more attention on the root causes that drive these deaths.”

If you or someone you know has talked about contemplating suicide, call the National Suicide Prevention Lifeline at 1-800-273-8255, open 24 hours a day, seven days a week.