Since 1998, people all over the world have been living healthier and living longer. But middle-aged, white non-Hispanics in the United States have been getting sicker and dying in greater numbers. The trend is being driven primarily by people with a high-school degree or less.

That's the sobering takeaway from a paper in the Proceedings of the National Academy of Sciences published this week.

Mortality Rate for 45-to-54-Year-Olds, By Country

Key: U.S. White non-Hispanics (USW), US Hispanics (USH), and six comparison countries: France (FRA), Germany (GER), the United Kingdom (UK), Canada (CAN), Australia (AUS), and Sweden (SWE). (PNAS)

The study authors sum it up:

Between 1978 to 1998, the mortality rate for U.S. whites aged 45 to 54 fell by 2 percent per year on average, which matched the average rate of decline in the six countries shown, and the average over all other industrialized countries. After 1998, other rich countries’ mortality rates continued to decline by 2 percent a year. In contrast, U.S. white non-Hispanic mortality rose by half a percent a year. No other rich country saw a similar turnaround.

That means “half a million people are dead who should not be dead,” Angus Deaton, the 2015 Nobel laureate in economics and co-author of the paper, told The Washington Post. “About 40 times the Ebola stats. You’re getting up there with HIV-AIDS.”

The reasons for the increased death rate are not the usual things that kill Americans, like diabetes and heart disease. Rather, it’s suicide, alcohol and drug poisonings, and alcohol-related liver disease.

The least-educated are worst off: All-cause mortality among middle-aged Americans with a high-school degree or less increased by 134 deaths per 100,000 people between 1999 and 2013, but there was little change in mortality for people with some college. The death rate for the college-educated fell slightly.

Causes of Increased Mortality

Among white non-Hispanics ages 45–54 (PNAS)

White Americans in this age category are also experiencing worse self-reported health, the authors write, and one in three say they experience chronic joint pain.

The PNAS analysis represents a confluence of several public-health disasters that have slammed white Baby Boomers in recent years.

Deaths from drug overdoses among people aged 45 through 64 increased 11-fold between 1990 and 2010, and nearly 90 percent of people who try heroin for the first time these days are white. (Most found heroin through prescription painkillers, which treat the chronic pain this age group struggles with, but can also make it worse.)

In January, a CDC Vital Signs report found that alcohol poisoning kills more than 2,200 Americans a year, three-quarters of them adults aged 35 to 64. A 2012 Health Affairs study found that life expectancy for white, female high-school dropouts has fallen so much over the past 18 years that these women are now expected to die five years younger than their mothers did.

Obviously, no one can be blamed for his own addiction or depression. But the causes of death this study highlights are the kinds of things—drinking, doping, suicide—that people who feel good about their lives don’t tend to do.

So, what’s eating less-educated Boomers?

One persuasive explanation, and one the researchers put forth, is financial strain. Jobs in fields like manufacturing and construction, which were historically filled by people without college degrees, have been evaporating quickly over the past 15 years. As I’ve written previously, less-educated people are more likely to be unemployed and to make less, so they struggle to afford things like therapy, gym memberships, and recreation that isn’t drugs. Without jobs, they may lack the social networks and sense of purpose that have shown to reduce mortality.

Nearly half of Americans in their 40s and 50s don’t have enough money saved for retirement to live as they’re accustomed to, even if they work until they’re 65. All of this is crashing down on Boomers, who were raised on the promise of the American Dream.

As Deaton and his co-author, his wife and fellow Princeton economist Anne Case, put it, “After the productivity slowdown in the early 1970s, and with widening income inequality, many of the baby-boom generation are the first to find, in midlife, that they will not be better off than were their parents.”

Deaton and Case note that middle-aged people in other countries also faced dire financial straits, especially during the 2009 recession. Yet they’re not dying like American 50-somethings are. One difference is that in those countries, comfortable pensions for retirees are guaranteed, so the prospect of an impoverished retirement might not loom as large in Europe as it does here.

“The U.S. has moved primarily to defined-contribution pension plans with associated stock market risk, whereas, in Europe, defined-benefit pensions are still the norm,” Deaton and Case write. “Future financial insecurity may weigh more heavily on U.S. workers.”

Tragically, that weight seems to be crushing these Americans before they can even retire.