Fog envelops the Golden Gate Bridge in San Francisco, California. (Kevin Lamarque/Reuters)
Matthew Nock is a Professor of Psychology at Harvard University and recipient of a MacArthur Fellowship for his research on suicide.

It populates our most ancient stories, spelling the ends of figures both infamous and innocent, from to Brutus to Judas to Juliet — but we still don’t fully understand suicide. Are the causes hereditary? How much does brain chemistry matter? What are the best ways to detect the impulse? Despite decades of research, scientists, clinicians and counselors are just beginning to unlock the mysteries of self-inflicted death. Sadly, the federal government currently allocates more money to problems like headaches, Lyme disease and lupus than to suicide, according to the National Institutes of Health; no other leading cause of death (in the United States, it is No. 10) has so little money dedicated to it. The absence of consistent, well-funded, quality research has led to a proliferation of myths about suicide and the people whose lives it claims.

1. We’re currently experiencing a suicide epidemic.

The Centers for Disease Control and Prevention released new data last month showing that the suicide rate in the United States rose between 1999 and 2014. Many media outlets, including the Guardian, the Washington Times and Foreign Policy, reported this as “an epidemic.”

These reports are misleading in several ways. Suicide is neither a disease nor contagious, so it doesn’t fit the literal definition of an epidemic. But the metaphorical use of “epidemic” doesn’t match, either: Suicide is not actually gaining sudden prevalence. The high rates of suicide reflected in the CDC’s report are not new. Yes, the rate in the United States has increased over the past 15 years or so, but it decreased over the 15 years before that. Today, 13 of every 100,000 people in the United States kill themselves; in 1914, 16 per 100,000 did.

Suicide has always been a major public health problem. It is the 10th leading cause of death in the United States, while worldwide, more people die from suicide than from wars, genocide and interpersonal violence combined — more than 800,000 every year, according to the World Health Organization. This means that we are each more likely to die by our own hand than by someone else’s. Unfortunately, that’s nothing new.

2. Suicides are most common during the winter holidays.

The notion that suicides peak during the holiday season is a longtime misconception with cultural precedent in films like It’s a Wonderful Life. In 2014, the Annenberg Public Policy Center at the University of Pennsylvania found that 70 percent of news articles linking the holidays and suicide between November of 2013 and January of 2014 suggested that suicides surge during the holiday season.

It’s easy to see why people might believe this myth: During the winter holiday season, there are fewer hours of sunlight, meaning shorter days and longer nights. It is cold and dreary. And while many people cheerily spend time with family and friends, others are not so fortunate and are left feeling sad and lonely. Sounds like the time of year when the suicide rate goes up, right?

Wrong. The rate is consistently highest in the spring, specifically in April and May. Experts do not fully understand why this might be the case, although one recent study by researchers from the University of Vienna, published in the journal JAMA Psychiatry, showed that as hours of sunlight increase, so does the risk of suicide. The authors speculate that sunlight could boost energy and motivation, thus giving people who are depressed the ability to take action and make a suicide attempt.

3. Most suicides are impulsive acts.

Suicide is often described as an act born of a sudden, fatal decision. “Indeed, many people who commit suicide are more momentarily desperate than classically depressed,” Elisabeth Rosenthal wrote in a 2013 New York Times article. “The role of impulsiveness is one of the saddest things about suicide,” Business Insider opined after actor Robin Williams’s death in 2014; the nonprofit Brady Campaign to Prevent Gun Violence says on its website that “impulsivity” is “the link between guns and suicide.” In 2015, Vox’s Ezra Klein echoed that sentiment, tweeting that “suicide is impulsive, and can be prevented if it fails.”

In reality, most people who attempt to kill themselves make a plan to do so, and even those classified as “impulsive” often have suicidal thoughts before they try it, according to a 2007 Australian study . (In that same study, only about 25 percent of people who attempted suicide considered their behavior to be impulsive.) Likewise, a recent review of research on this topic concluded that the link between impulsivity and suicide is weak. This is good news for prevention efforts: According to a 2002 study published in the American Journal of Psychiatry, nearly half of those who die by suicide visit their doctors in the month before their deaths, and nearly two-thirds tell someone that they want to die or are thinking about suicide. That provides not only clues that they are at risk but also opportunities to help them.

4. There is a “suicide gene.”

Suicide is a perplexing problem. As with many other leading causes of death that we don’t fully understand (including cancer and Alzheimer’s ), many of us want “the cause” to be discovered so we can devise a treatment. We want, in short, a “suicide gene.” And several studies published in the past few years have identified aspects of DNA that seem to differ between some people who have died by suicide and those who haven’t. When such studies are reported in the media, they are often described as having found “a gene for suicide.” In 2014, the Huffington Post announced that “this gene could tell you who is at risk for suicide,” while similar headlines ran in Forbes and the Guardian. But things aren’t so simple.

Unfortunately, there is no gene for suicide. Suicide is the result of a complex interaction among many factors that cannot be reduced to a single piece of genetic code. And none of the genetic factors that have been linked to suicide are unique to suicidal behavior. Instead, they seem to be markers for things like a tendency to have low mood, sleep problems and anxiety — all of which increase the risk of suicidal behavior but don’t code for it specifically, and often exist in non-suicidal people. For example, one of the most recent and lauded studies detected a genetic defect that could affect how the brain manages stress hormones — which is perhaps related to suicidal behavior but far from its only cause.

Ultimately there is no one cause, genetic or otherwise, for suicide. As Kenneth Kendler put it in a 2005 article in the American Journal of Psychiatry: “The phrase ‘X is a gene for Y’ . . . [is] inappropriate for psychiatric disorders. The strong, clear, and direct causal relationship implied by the concept of ‘a gene for . . .’ does not exist for psychiatric disorders.”

5. We know how to prevent suicide.

Many organizations and public health campaigns say suicide is preventable. The National Institute of Mental Health, for instance, dubs suicide a “major, preventable mental health problem.” After all, it’s a behavior based on human decision-making, and in that sense it can theoretically be spotted and stopped.

But we are not yet very successful at this. There are many well-intentioned prevention programs out there, but we have very little data on which ones work and which ones don’t. Likewise, several proposals for reducing suicide rates have been made over the years — among them restricting gun access (as posited by a 2015 paper analyzing suicides in Connecticut and Missouri) or doing more screening (as suggested by the Substance Abuse and Mental Health Services Administration). But studies haven’t been carried out.

We do know what factors put people at elevated risk for suicide — depression, substance use, a family history of suicide — and according to a study published this year in the journal PLoS Medicine, some treatments appear to reduce the chance of reattempts among those who have previously tried to kill themselves. But we have no programs backed up by evidence from randomized controlled trials, the highest standard, showing that they stop people from ever attempting suicide. Our best bet for preventing suicide is to ramp up research and hopefully shed more light on this troubling phenomenon.

Twitter: @NockLabHarvard

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