As Suicide Rates Rise, Scientists Find New Warning Signs
Computer algorithms, biomarkers and other advanced techniques help flag trouble earlier. As Suicide Rates Rise, Scientists Find New Warning Signs
Scientists are making headway in the search for solutions to one of the most vexing problems in mental health: How to predict who is at risk for suicide.
Researchers are hunting for so-called biomarkers, such as patterns of brain activity on fMRI scans or levels of stress hormones in the blood, linked to suicidal thoughts and acts. They are creating computer algorithms, fed with tens of thousands of pieces of data, to come up with measures of risk. They are looking at sleep patterns and even responses to specialized computer tasks that can reveal unconscious biases toward self-harm.
The need is great. The reality is that it is very hard for psychiatrists and psychologists to identify who is at risk for suicide. They rely heavily on simply asking patients.
But people often conceal their plans. Indeed, researchers at Harvard University and Massachusetts General Hospital found that clinicians were no more accurate than chance in predicting which patients visiting a psychiatric emergency room were likely to attempt suicide in the next six months.
Widely accepted risk factors, like being male, having a history of mental illness and experiencing stressors like a job or relationship loss, are often not specific enough to be much help.
Meanwhile, rates of suicide deaths are rising in the U.S. The rate jumped 24% from 1999 to 2014, from 10.5 to 13 per 100,000 people, according to an April 2016 report from the Centers for Disease Control and Prevention.
“It is a leading cause of death and we just don’t have a handle on it,” says Matthew K. Nock, a psychology professor at Harvard and one of the country’s leading suicide researchers.
While depression is the mental illness that is most strongly associated with suicidal thoughts, it doesn’t often lead to suicidal acts. Recent research has shown that it is other mental illnesses, like anxiety disorders, problems with impulse control and addiction, that are actually more strongly linked to suicide attempts. Most first suicide attempts occur within a year of the onset of suicidal thoughts.
The National Institute of Mental Health recently launched a study that will use brain scans, blood draws and other tests to identify biomarkers that are related to imminent risk for suicide.
The study will enroll 170 people total and compare four groups. Fifty will be recruited within two weeks of a suicide attempt or severe suicidal thoughts. (Patients are enlisted from a hospital emergency room or inpatient unit.) A group of 40 subjects will have a history of suicide attempts but none in the past year. Another 40 will have anxiety or depression symptoms but no suicidal thoughts or behavior. The last 40 subjects will be healthy controls.
Another study from the same NIMH group has found that, among severely depressed subjects, spending more time awake between 4 a.m. and 5 a.m. (as measured by a sleep study called polysomnography) is linked to increased risk of suicidal thinking the next day. Results of the study were presented at an American Society of Clinical Psychopharmacology meeting in May. Both NIMH studies are also testing the drug ketamine as a potential treatment for suicidal thoughts.
“Those guys are probably lying in bed and ruminating more,” says Carlos A. Zarate Jr. , chief of the section on the neurobiology and treatment of mood disorders at NIMH.
Researchers are also looking into levels of the stress hormone cortisol as a potential marker for risk for suicide attempts. One study published in 2016 in the journal Neuropsychopharmacology followed 208 people whose parents had a mood disorder. It found that those subjects with a history of suicide attempts had lower baseline cortisol levels and lower cortisol output in response to a stressful task like making a speech or doing math. That was true even compared with those who made no actual attempts but exhibited suicide-related behavior such as suicidal thoughts that led to a medical referral.
Dr. Nock and colleagues are finishing up a study to create a measure of individual suicide risk. The researchers used the medical records of 1.7 million people who are patients at a large health-care system.
Computers analyzed more than 30,000 different risk factors, including traditional ones like age and mental-health history. But some surprising issues—such as gastrointestinal problems, infections and injuries like rib fractures—were tied to increased risk.
Dr. Nock says that some of these may be self-inflicted or related to impulsive behavior. Using the historical data, the approach was able to detect 45% of suicidal acts an average of about three years before the event.
A study using similar methods looking at suicide risk among U.S. Army soldiers in the year after hospitalization for psychiatric issues was published in 2015 in JAMA Psychiatry. The algorithm was able to predict about 53% of the suicides in that high-risk period.
Unconscious biases may also reveal risk. Dr. Nock and co-workers at Harvard and Mass General have used a seemingly simple computer task that gets at what is known as implicit cognition. People are presented with several words that represent life (“thrive” or “breathing,” for example), death (“lifeless,” “suicide”) and “me” (“I”, “self”) and “not me” (“they,” “other”).
In a study published in 2010 that followed 157 people who had visited a psychiatric emergency room, subjects are asked to classify words into categories. The study found those subjects who were quickest at classifying death and “me words” into the same group had three times the rate of suicide attempts in the next six months compared with those who were quickest at linking life and “me words.” (A past suicide attempt is the strongest predictor of a future one.)
The science on the new methods of prediction is still in its early stages. No approach is likely to identify everyone at risk. But the hope is that better prediction could give doctors and families time to get vulnerable patients into treatment, tweak medications or even secure a pre-emptive hospital admission. Researchers are also working on new treatments to better target suicidal thoughts and behavior.
The Mystery Around Middle-Age Suicides
The recent suicides of two well-known figures—celebrity chef Anthony Bourdain and fashion designer Kate Spade —underscore a sobering reality: Suicide rates for people in middle age are higher than almost any other age group in the U.S. and rising quickly.
A report released today from the Centers for Disease Control and Prevention showed that suicide rates for women 45 to 64 increased nearly 60% between 2000 and 2016. For men of the same age the suicide rate increased almost 37% over that time.
No group of women saw a higher suicide rate. Among men, only those 75 and over had higher rates than the 45-to-64 group.
Mr. Bourdain was 61 at the time of his death. Ms. Spade was 55.
Overall, suicide rates in the U.S. increased 30% between 2000 and 2016. A separate CDC analysis released this month found that suicides have risen in almost every state.
Experts say mental illness, substance abuse, loneliness and financial and relationship problems all have contributed to suicide rates increasing. But it’s unclear why suicide appears to peak in middle-aged people.
“Life satisfaction hits an all-time low in middle age. This dip in happiness is known as the U curve,” says Samantha Boardman, a clinical instructor in medicine and psychiatry at Weill Cornell Medical College in New York City.
“Depression and stress are particularly high in this age group. Juggling responsibilities and managing multiple roles takes a toll and can lead to feeling overwhelmed, a loss of control and despair.”
Factors such as a decline in physical health and chronic pain can also contribute to suicide, Dr. Boardman says. Those stresses can feel particularly difficult for longtime sufferers of depression.
The five most common stressors linked to suicide among middle-age adults were problems with intimate partners, job/finances, health, family and criminal/legal problems, according to a 2016 study in the American Journal of Preventive Medicine.
The CDC found the suicide rate for women 45 to 64 climbed to 9.9 deaths per 100,000 people in 2016, up from 6.2 in 2000. For men in that age group over that time, the suicide rate rose to 29.1 deaths per 100,000 in 2016, up from 21.3.
Catherine Burnette, an assistant professor at Tulane University School of Social Work in New Orleans, says if people have lived with untreated depression over time, it can implode in their 40s, 50s or 60s.
“If people have been drinking or using substances as a coping mechanism, the cost of that might peak at those ages, too,” Dr. Burnette says.
For accomplished or well-known people, isolation can be a risk factor, she says. “Social connection is one of the biggest antidotes to suicide,” she says. “I think it can be pretty isolating to be a celebrity, where outside people may seek social opportunities rather than social connection.”
Anne Case, a professor of economics and public affairs at Princeton University, says the demographic group really driving middle-age suicide rates is white people without a four-year college education. African-Americans have lower suicide rates that haven’t increased, she says.
“We think whites without a B.A. find that they don’t have the same promising future that the generation before them had,” Dr. Case says. “It’s much harder to find a good job, a job with a ladder up.”
Increasing reports of patients experiencing physical pain may also play a role, she says. “We know that pain is a trigger for suicide,” she says.
Jeffrey Lieberman, chairman of psychiatry at Columbia University, says 90% of people who die by suicide have pre-existing mental disorders, whether they have been diagnosed and treated or not. The top four conditions associated with an increased risk for suicide are depression, bipolar disorder, schizophrenia and post-traumatic stress disorder.
Another major risk factor for suicide is substance abuse, he says. Heavy drug or alcohol abuse alters the connectivity of neural pathways involved in reward and the emotional and cognitive processing of normal experiences. “It produces chemical changes and ultimately structural changes in a way that becomes permanent,” Dr. Lieberman says.
Mr. Bourdain had spoken openly about past problems with substance abuse.
For women, hormonal changes that come with menopause may play a role. Menopause results in a drop in estrogen, which can cause changes in brain function, which not everyone is able to adapt to, he says.
Inger Burnett-Zeigler, a clinical psychologist and assistant professor in the department of psychiatry and behavioral sciences at Northwestern Medicine, says job-related concerns can play a role for men in particular, who have higher rates of suicide overall.
Men are also less likely to identify that they have a mental-health problem or may need treatment. “So there’s less support connecting them to treatment,” he says.
“People of all levels of success and those who have achieved great success are still at significant risk for having emotional and mental difficulties,” Dr. Burnett-Zeigler says. “Sometimes people who are highly successful also have an increased level of anxiety around maintaining that level of success, or fear of loss of all that they’ve achieved. So I think we should be mindful that even those who to the outside world are quite successful can still have a lot of emotional difficulties that are not obvious to others.”Go back