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The five-factor model of personality has been a popular focus of research for decades. The five traits measured in the model (openness to experience, conscientiousness, extroversion, agreeable, and neuroticism) have been found to predict a wide range of important life outcomes. For example, the personality trait of conscientiousness is, after general intelligence, the single best predictor of academic or work performance. (To take a five-factor personality test yourself, try the 120-item IPIP NEO.)
It has been long known that certain personality disorders, such as Borderline Personality Disorder, are associated with a higher than usual risk for suicide. Less well known is the fact that 5 percent of people with Antisocial Personality Disorder eventually die by suicide. Ansell and colleagues (2015) followed 431 patients with personality disorders for 10 years. Over that time, 13.5 percent of the patients made one or more suicide attempts (range = 0 to 11). As expected, a diagnosis of Borderline Personality was found to increase the risk of a future suicide attempt, but perhaps unexpectedly, a diagnosis of Narcissistic Personality Disorder was found to increase the risk of multiple future attempts.
In recent years, several researchers have investigated the relationship between suicide risk and the five-factor personality traits. Duberstein and colleagues (2000) studied 81 depressed inpatients aged 50 or older. They found that higher levels of neuroticism and openness to experience were both associated with having a history of suicidal ideation. In addition, lower levels of extraversion were associated with having a history of past suicide attempts.
McCann (2010), in a much different, population-based study, looked at the relationship of five-factor traits at the state level and state suicide completion rates. (State populations differ on personality trait means; for example, people in Nebraska score lower on neuroticism than do people in New Jersey.) The data showed that states with higher levels of neuroticism and lower levels of agreeableness had increased rates of death by suicide. In fact, those two personality traits combined accounted for about half of the variance in suicide rates among the 50 states.
Several other studies have been conducted on large samples. Bluml and colleagues (2013) looked at 2,555 German citizens and assessed their Big Five personality traits and their suicide risk. They found significant differences in the findings between men and women. For females, suicide risk was increased when neuroticism was higher and when openness to experience was higher. For males, however, suicide risk decreased in the presence of higher extroversion and higher conscientiousness.
In a large study of male members of the Iranian armed forces (N=1,659), Soltaninejad and colleagues (2014) found significant correlations between Big Five personality traits and suicidal ideation. Neuroticism was the stronger predictor of current suicidal thinking (r = .323), followed by extroversion (r = -.306), and then by agreeableness (r = -.227). In other words, higher neuroticism, lower extroverson, and lower agreeableness increased the risk of suicidal ideation in this sample.
The largest study of this kind that I am aware of was published by Batty and colleagues in 2018. They monitored a sample of 464,251 adults in several countries over a period of about 8 years. Over that time period, 270 members of the sample died by suicide. They found that higher levels of neuroticism significantly increased the suicide risk and that lower levels of agreeableness also contributed, but less dramatically.
What can we take away from such studies? In general, the findings seem consistent with what some personality theorists have dubbed the "Misery Triad," i.e., higher neuroticism, lower conscientiousness, and lower extroversion. This combination of traits suggests a greater sensitivity to emotional pain, a lack of effectiveness in solving one's problems and resisting impulses, and a deficit of social support. The studies which implicate lower agreeableness add to the "lack of social support increases suicide risk" hypothesis, as people who are hostile and untrusting are less likely to have supportive social networks than people who are cooperative and kind.
In sum, each of the five-factor model personality traits has been implicated in the phenomenon of suicide. Neuroticism is the trait most strongly implicated—persons with very high levels of that trait should be helped by a course of psychotherapy, which could teach them how to better manage their negative emotions. In some cases, intervention with psychiatric medication may be appropriate as well.
Lower levels of both extroversion and agreeableness have also been associated with suicide risk. In our increasingly atomized society, we need to make a far greater effort to build strong family relationships, nurture friendships, and contribute to our communities. As the suicide researcher Thomas Joiner once said, if he was given a large sum of money to fund a Public Service Campaign to prevent suicide, one message he would promulgate is: "Keep your old friends. Make some new ones."
Lower conscientiousness is a risk factor for two reasons: 1) a person lower in conscientiousness is more impulsive and may be more at risk of making an ill-considered decision to attempt suicide; 2) this trait is associated with worse performance in school and at work. It is important to remember that about a third of suicide completers are unemployed at the time of their deaths (contrast this to a national unemployment rate of about 4 percent). As a nation, we need to attend more to those of us who are unable to successfully compete in our meritocratic, hypercompetitive consumer society. At the clinical level, it is critical to help patients develop a "crisis plan" with specific steps to take should one begin to feel increasingly suicidal.
Finally, it surprised me that higher levels of openness to experience were associated with increased risk of suicidal ideation and, in at least one study, with higher suicide risk. I have met many people who, when asked if they have ever thought seriously about ending their life, replied, "Well, hasn't everyone?" The answer, which surprises them, is that, no, actually, most people have never seriously considered ending their own lives. The approximately 20 percent (or one in five) who have, however, should realize that such thoughts are not "normal" or "ordinary," and that it is critical that they share what they have been thinking with someone who cares about them.
