From The Quarterly, Spring 2015

As public health experts debate the best ways to reduce suicides––a top-five leading cause of death among Americans aged 10 to 54 in 2013––new research calls attention to the importance of early intervention based on long-term risk factors.

In a study published in the February 2015 issue of JAMA Psychiatry, a team led by NARSAD Scientific Council member and 2008 Distinguished Investigator grantee J. John Mann, M.D., probed the extent to which suicidal behavior in a parent gets passed on to children. The investigators tracked 701 children of 334 people diagnosed with mood disorders for an average of six years to identify factors that predicted suicide attempts among the children.

The research team also included 2001 NARSAD Distinguished Investigator grantee David A. Brent, M.D., 2013 Young Investigator grantee Nadine M. Melhem, Ph.D., and 1996 and 1998 Young Investigator grantee John G. Keilp, Ph.D.

The investigators found that having a parent who had attempted suicide made it nearly five times more likely that one of their children would make an attempt. It has been known that both genetic and non-genetic factors related to the predisposition for suicidal behavior or to psychiatric illnesses that trigger suicidal behavior, are transmitted in families. This study sought to identify the factors responsible for such familial transmission.

Suicide attempts were more likely among those children who, like their parents, were diagnosed with a mood disorder such as major depression or bipolar disorder. Such diagnoses appear to be needed for the manifestation of suicidal behavior, about a year before the first attempt. Most people diagnosed with depression do not attempt suicide because they do not have a predisposition to suicidal behavior.

Independent of family history of depression, impulsive and aggressive behavioral traits among the children also made it more likely that they will attempt suicide. This indicates a greater propensity to act on emotions. Those with pronounced aggressive and impulsive traits are also more likely to be diagnosed with a mood disorder; the combination puts them at greater risk for a suicide attempt.

These findings highlight the importance of three long-term risk factors in predicting suicide attempts: a family history of suicide attempts, a family history of mood disorders, and a personal history of impulsive aggression. It’s important that such families focus on early detection and treatment of mood disorders and aggressive-impulsive traits, the researchers say.

In recent months, public officials have taken steps to make it more difficult for people to attempt suicide. There are plans to build suicide-prevention structures around San Francisco’s Golden Gate Bridge and New Jersey’s George Washington Bridge.

Efforts on all fronts may be needed to address troubling recent developments in suicide research, including the increase found in suicide rates among African American children between 1993 and 2012, as reported in JAMA Pediatrics on May 18th. This was a period in which suicide rates went down among white children.