Suicide rates among middle-aged people are increasing. The trend seems to be driven by the Baby Boomers entering into middle age, when chronic diseases start to appear.

The study, published in the journal Public Health Reports, shows middle-age suicides to be at odds with the overall U.S. suicide rate, which has been decreasing. According to sociologist Ellen Idler of Emory University, people aged 40-59 have had a longtime moderate suicide rate.

Idler said, “The findings are disturbing because they’re a reversal of a long-standing trend.”

Using data from the National Center for Health Statistics and the U.S. Census Bureau, Idler and colleagues tracked suicide rates from 1975 to 2005. By 2000, most people aged 40-59 were Baby Boomers; the suicide rate started climbing steadily for these middle-age ranges. There was an increase of over 2% per year per man, and more than 3% for women from 1999 to 2005.

Data from 2006 and 2007 indicate that the trend toward more middle-age suicides is continuing, according to Idler. The National Center for Health Statistics lists the suicide rate for 45-54-year-old as 17.7 deaths per 1000,000 people in 2007. For the 25-34-year-old age group, the suicide rate is 13 deaths per 100,000 people and 12.6 deaths per 100,000 in the 65-74 age group.

The post 1999 increase in middle-aged suicide has been particularly dramatic for those who are unmarried and less educated. Suicide rates in men aged 40 to 49 who had some college but no degree increased 16.3% between 2000 and 2005, while the suicide rate in men aged 50-59 went up 29.6%. Women showed a 30% increase in the suicide rate for both ages for women with some college but no degree.

Men and women with a high school degree or less also became more likely to commit suicide. Rates in men with a high school diploma increased 11.7% in the 40-49 age group and 27% in the 50-59 age group.  Women saw their suicide rate increase by 15 and 17%.

Middle-participants with a college degree appeared largely protected from the trend.

The Baby Boomers also experienced higher suicide rates during their adolescent and young adulthood, doubling the rate for those age groups at the time. Their suicide rate then declined slightly and stabilized, before beginning to increase again in midlife.

“You might think higher rates in adolescence would lead to lower rates later because the most suicide prone people would be gone, but that doesn’t appear to be the case,” Idler said.

Studies show that knowing someone who committed suicide is a risk factor for people who later kill themselves.

“The high rates in adolescence could actually be contributing to the high rates in middle age,” said Idler, who also credits substance abuse and the onset of chronic diseases as contributing to Baby Boomer suicides.

“As children, the Baby Boomers were the healthiest cohort that had ever lived, due to the availability of antibiotics and vaccines. Chronic conditions could be a rude awakening for them in midlife than they were for earlier generations.”