White middle-aged Americans are dying at an increasing rate, a new analysis of government data shows, a startling turnaround suggesting a rising toll of addiction and mental-health issues is reversing decades of gains in longevity.

Suicides, alcohol and drug overdoses, and death from chronic liver diseases largely drove the reversal, which occurred between 1999 and 2013, according to the analysis published Monday in the Proceedings of the National Academy of Sciences. The turnaround occurred primarily among men and women between the ages of 45 and 54 with no more than a high-school education, but rates of those causes of death rose for wealthier middle-aged whites as well as whites in other age groups, according to the study.