A new study shows higher rates of suicide among middle age adults in recent years. CNN reports:

In the last 11 years, as more baby boomers entered midlife, the suicide rates in this age group have increased, according to an analysis in the September-October issue of the journal Public Health Reports.

The assumption was that “middle age was the most stable time of your life because you’re married, you’re settled, you had a job. Suicide rates are stable because their lives are stable,” said Dr. Paula Clayton, the medical director for the American Foundation for the Prevention of Suicide.

But this assumption may be shifting.

A sociologist explains:

“So many expected to be in better health and expected to be better off than they are,” said Julie Phillips, lead author of the study assessing recent changes in suicide rates. “Surveys suggest they had high expectations. Things haven’t worked out that way in middle age.”

Further,

Baby boomers (defined in the study as born between 1945 and 1964) are in a peculiar predicament.

“Historically, the elderly have had the highest rates of suicide,” said Phillips, a professor of sociology at Rutgers University. “What is so striking about these figures is that starting in 2005, suicide rates among the middle aged [45-64 years of age] are the highest of all age groups.”

The 45-54 age group had the highest suicide rate in 2006 and 2007, with 17.2 per 100,000. Meanwhile, suicide rates in adolescents and the elderly have begun to decline, she said.

“What’s notable here is that the recent trend among boomers is opposite to what we see among other cohorts and that it’s a reversal of a decades-long trend among the middle-aged,” said Phillips, who along with Ellen Idler, a sociologist at Emory University, and two other authors used data from the National Vital Statistics System.

Several theories have been proposed to explain this trend, including higher suicide rates among boomers during adolescence.

Baby boomers had higher rates of depression during their adolescence. One theory is that as they aged, this disposition followed them through the course of their lives.

“The age group as teenagers, it was identified they had higher rates of depression than people born 10 or 20 years earlier — it’s called a cohort effect,” said Clayton, from the American Foundation for the Prevention of Suicide, who read the study.

Others cite health concerns:

Some say health problems could be a factor in increased suicide rates among baby boomers.

Boomers have their share of medical problems such as high blood pressure, diabetes and complications of obesity.

“There’s a rise of chronic health conditions among the middle aged,” Phillips said. “In the time period from 1996 to 2006, we see fairly dramatic chronic health conditions and an increase in out-of-pocket expenditures.”

Some speculate that the increase in baby boomer suicides could be attributed to stress, the number of Vietnam veterans in the age group or drug use, which was higher in that generation. Boomers are also the “sandwich generation,” pressed between needs of their children and their aging parents who are living longer, but have health problems like Alzheimer’s or dementia.

Finally, economic woes may be to blame.

All this is unfolding in a lagging economy, meaning boomers could be affected by the “period effect.”

“One hypothesis is that the economic pressure during this period might be a driving force, with the recession in the early 2000s — loss of jobs, instability, increases in bankruptcy rates among middle age,” Phillips said.

Unemployment correlates with increased rates of suicide. People who are unmarried and have less education are also more at risk.