From The Quarterly, Spring 2015

Attempting suicide is among the strongest risk factors for future suicide completion. Thus there is great value in knowing which people are most likely to attempt suicide in the future, and to predict who among these attempters will ultimately die by suicide. These are among the leading goals of investigators.

Two recently published studies by 2013 NARSAD Young Investigator James Bolton, M.D., of the University of Manitoba, and colleagues, report progress, but remind us how difficult it is to predict suicidal behavior. One of the new studies is about people who were referred to psychiatric staff at two large hospital emergency departments; the other, about suicidal behavior in a large sample of people from the general population diagnosed with major depressive disorder (MDD).

On June 6th, Dr. Bolton and colleagues reported in the Journal of Nervous and Mental Disease the fate of 6,919 referrals to psychiatric services in two Manitoba hospitals over a 3-year period. Ultimately, 3,939 patients formed the basis of the study’s analysis, of which 104 returned to the ER after a suicide attempt within 6 months of their original ER visit.

After evaluating an extensive list of factors, the team concluded there were only two measures with predictive power regarding future suicide attempts: a history of suicidal thinking and previous suicide attempts. Still, neither of these factors, or other factors such as depression or hopelessness that did correlate to some degree with future attempts, could predict which specific patients would attempt suicide again. The two measures have a public health value, in helping to broadly guide evaluation and treatment, but no predictive value in individual cases.

A second paper by Dr. Bolton and colleagues, based on a U.S. survey of 34,000 non-institutionalized adults, appeared in the April-June 2015 issue of the Archives of Suicide Research. The researchers examined how stressful life events were associated with suicidal behavior. Focusing on the 6,004 survey respondents who had MDD, the team found a relationship between stressful life events—especially interpersonal problems with friends, coworkers or relatives, and severe financial difficulty—and the likelihood of a future suicide attempt.

The team noted that “despite the significant association found between some stressful life events and suicidal behaviors,” each of them, taken individually, has a relatively low “predictive” value—less than 10 percent. While they are important warning flags, particularly in someone thought to be at risk for suicide, stressful events cannot themselves predict whether a particular person is going to make a suicide attempt. Importantly though, these risk factors can guide evaluation: “Doctors should ask about recent stressful life events as part of their risk assessment of depressed persons,” the team concludes, “and may consider additional supportive psychotherapeutic approaches as part of their depression management.”