A history of attempting suicide has long been known as one of the strongest predictors of completed suicide. But a Mayo Clinic study finds it is even more dangerous than previously thought.

Researchers found the risk of suicide was nearly 60 percent higher than previously reported when based on a population-based cohort focusing on individuals making first lifetime attempts and including those whose first attempts were fatal.

This risk was dramatically higher for attempts using firearms. The population sample was identified through the Rochester Epidemiology Project.

“We hoped to address the shortcomings of earlier studies by including two groups previously overlooked by other studies,” said J. Michael Bostwick, M.D., a psychiatrist.

Bostwick is the lead author of the study published in the American Journal of Psychiatry.

“Our study enrolled individuals whose first-ever suicide attempt presented to medical attention. Not only did we include those who survived this initial attempt, but we also included those who died on their first attempt and ended up on the coroner’s slab rather than in the emergency room. These are large groups that have been routinely ignored in calculation of risk.”

Since suicide is one of the 10 most common causes of death in the U.S., it is a major public health concern. The study found that nearly 60 percent of people who attempted suicide died on their first attempt.

“Almost no other study in the literature includes individuals who die on that first attempt,” Dr. Bostwick adds.

“A large part of the reason that such a high proportion of the total suicides occurred on first attempt can be attributed to firearm usage.

“The results show that it is 140 times more likely for firearms to cause suicide, compared to all other methods. That means nearly three-fourths of all deaths at first suicide attempt were caused by using firearms. This shows that guns are, unfortunately, but not surprisingly, remarkably effective.”

The study also revealed that the male-female ratio was higher (1.7-to-1) among those making their attempts than what other studies previously purported.

Older age in men also is associated with higher suicide risk. Nearly one-third of men over 65 in the study killed themselves.

The Rochester Epidemiology Project diagnostic index was searched electronically to identify 1,490 Olmsted County residents whose first suicide attempt came to medical attention between Jan. 1, 1986, and Dec. 31, 2007. The study included 555 males and 935 females followed for three to 25 years.

While the study confirmed previous findings that the risk decreased in survivors given a follow-up psychiatry appointment, the vast majority of survivors, irrespective of gender, killed themselves within a year after the index attempt.

This underscores how important it is that survivors have psychiatric follow-up scheduled after the first attempt and how the first year following a suicide attempt is a critical window for a repeat fatal attempt.

Source: Mayo Clinic/EurekAlert