article

03.24.09

Is There a Suicide Gene?

Depression and bipolar disorder may be in your DNA—but is suicide? Several high-profile families have been plagued by the phenomena. Casey Schwartz investigates.

Depression and bipolar disorder may be in your DNA—but is suicide? Several high-profile families have been plagued by the phenomenon. Casey Schwartz investigates.

The news on Monday that Sylvia Plath’s son, Nicholas Hughes, had killed himself, reopened a macabre chapter of literary history. Obituaries revealed spare and suggestive details. Hughes, the son of the poet Ted Hughes, lived in Alaska and worked as a biologist, studying the travel patterns of fish. Recently, however, he had left his job to focus on pottery making. Hughes was still an infant when his mother committed suicide in 1963 by putting her head in a gas oven; he was seven when his father’s second wife, Assia Wevill, killed herself (and her four-year-old daughter) by exactly the same means. And 40 years later, on March 16, 2009, Hughes took his own life, hanging himself in his Alaska home.

It is difficult to imagine what gravitational force in Ted Hughes’ unlucky orbit could explain this protracted pattern. But it is clear that suicide can run in families.

A study in the Archives of General Psychiatry found that children whose parents had attempted suicide were six times as likely to try taking their own lives.

There are other famous examples, including the spectacularly disastrous fate of the Hemingway family—beginning with the suicide of Ernest Hemingway’s father, Clarence, continuing to Ernest Hemingway’s own final gunshot, the suicide of his two siblings Ursula and Leicester, and, two generations later, that of his granddaughter, the actress Margaux Hemingway.

A recent biography of the philosopher Ludwig Wittgenstein describes an equally tragic family history. Three of his brothers committed suicide, two of his sisters married men who went mad, one of whom, in keeping with family tradition, eventually killed himself. Ludwig himself struggled with suicidal thoughts; as did his one surviving brother, a renowned pianist even after he lost one of his arms in World War I.

The Pulitzer Prize-winning writer J. Anthony Lukas, the author of Common Ground, who hanged himself with a bathrobe sash in 1997, also had a family history of suicide. His mother, an actress, took her own life with a razor blade when he was eight years old.

There is more than just anecdotal evidence behind the claim that the suicide of one family member increases the chance that other family members will attempt suicide, or successfully carry it out. A study in the Archives of General Psychiatry published in 2002 found that children whose parents had attempted suicide were six times as likely to try taking their own lives. Twin and adoption studies have revealed that a disposition toward suicidal behavior is partially heritable. Researchers have scrutinized the phenomenon, struggling to untangle the psychological factors from the genetic.

Of course, suicide is closely associated with a number of psychiatric conditions, such as depression and bipolar disorder, which have well-established genetic links. But studies have shown that suicide can be independently inherited.

“We grow up and we learn how to be by either imitating or negating our parents,” says Dr. T. Byram Karasu, university chairman and professor at the Albert Einstein College of Medicine at Yeshiva University. “So if you identify with one parent who happened to be suicidal, you may end up having suicidal ideation even though you’re not depressed. It becomes like a norm.”

According to Karasu, a parent’s suicide can provide a model of how one deals with life—a lethal example for children who have also inherited that parent’s biological predisposition. Of course, the psychological legacy is all but impossible to quantify.

“How do you even capture in some kind of research instrument ‘identification with a suicidal parent?’” remarks Peter Freed, a psychiatrist at Columbia University.

Within this thicket of factors, researchers are searching for genetic clues. The idea that a handful of genes could ever be confidently singled out in explaining the act of suicide—in all of its complexities and variations—is deeply improbable. But a group of researchers led by Columbia University psychiatrist John Mann published a study earlier this year that directly grapples with the issue. The researchers attempted to break down suicidal behavior into individual characteristics that can be more closely identified with specific genes. Their approach focused on what is known in the genetics world as “endophenotypes"—heritable traits that are associated with both the gene and the illness, but not synonymous with either—and which include impulsivity, major depressive disorder, and natural stress hormone response.

There is no one reason for why someone would choose to end their own life, but the suicide of any public figure seems to ignite a reflexive need to speculate. In the case of Nicholas Hughes, it might seem self-evident to point to the tragic luster of his family. But for now, the explanation eludes us.

Casey Schwartz is a graduate of Brown University. She's working on a book about the brain world.