After nearly six decades of increasing life expectancy, U.S. average lifetimes have been declining since 2014, according to a bleak new report published Tuesday in the Journal of the American Medical Association.

Drug overdoses — mainly opioids —suicides, alcoholic liver disease, and conditions related to substance use disorder are the main factors killing young and middle-aged adults years before their time, according to the research from the Center on Society and Health at Virginia Commonwealth University.

Midlife mortality — defined as deaths of people ages 25 to 64 — increased from 328.5 deaths per 100,000 people in 2010 to 348.2 by 2017.

Average U.S. life expectancy peaked at 78.9 years in 2014, but started sliding until it hit 78.6 years in 2017, according to the study.

The biggest increases in midlife death rates from 2010 to 2017 were in the New England states and the Ohio Valley. Pennsylvania was not far behind, with a 14.4% midlife mortality increase in the period studied. New Jersey’s rate rose by 7.6%.

These reversals come after decades of Americans expecting they would outlive previous generations.

“To see life expectancy going in the wrong direction has not occurred in this country for a long time,” said Philadelphia Health Commissioner Thomas Farley.

A comprehensive local report, “Health of the City,” released in January, found that in 2017 overdose outstripped all other causes of death in Philadelphia except for heart disease and cancer, both of which are far more common in older people. Gun violence deaths were also high.

“Every day, too many young people in Philadelphia and across the nation are dying early from preventable causes,” said Raynard Washington, chief epidemiologist for the city Department of Public Health. “Substance use, gun violence, and smoking- and obesity-related chronic illnesses are the primary causes of premature death among Philadelphians.”

In May, Gov. Tom Wolf’s administration announced the creation of a suicide prevention task force, citing an “epidemic” of people taking their lives. In 2018 alone, 2,030 people killed themselves in Pennsylvania. According to a report from the federal Centers for Disease Control and Prevention, the commonwealth’s suicide rate rose 34% between 1999 and 2016.

In addition, people ages 25 to 34 represent the largest increase in alcohol-related liver disease deaths, according to published reports.

“It seems like we’re seeing more and more young people with end-stage liver disease or severe alcoholic hepatitis with underlying cirrhosis,” said Keira Chism, a psychiatrist with Thomas Jefferson University Hospital’s Transplant Institute.

The U.S. mortality rate increase is in stark contrast to what is happening in other developed nations, Steven H. Woolf, director emeritus of the VCU center and lead author of the study, told the Washington Post.

“It’s supposed to be going down, as it is in other countries,” Woolf said. “The fact that that number is climbing, there’s something terribly wrong.”

Some of the new report’s findings include:

  • The New England states and the Ohio Valley (Ohio, Kentucky, West Virginia and Indiana) saw the highest rates of increase in midlife deaths. However, Pennsylvania, Ohio, Indiana, and Kentucky together made up one-third of the unexpected midlife deaths.
  • Men had higher overall mortality rates than women. However, more women appear to be succumbing to causes that in the past were much more common for men. For example, between 1999 and 2017, fatal drug overdoses among women increased almost 486%, compared with a 351% increase among men.
  • Among people of color, non-Hispanic blacks experienced the largest increase in fatal drug overdoses — a nearly 172% increase from 2010 to 2017.
  • Deaths from chronic liver disease and cirrhosis overall increased almost 41% from 1999 to 2017, but among 25- to 34-year-olds, the increase was almost 158%.

People in crisis can call the National Suicide Prevention Lifeline at 800-273-TALK (-8255) or use the Crisis Text Line by texting TALK to 741741.

Staff writer Aubrey Whelan contributed to this article.