As seen in Psychology Today.

The United States is experiencing a suicide crisis. A report issued by the Centers for Disease Control and Prevention last year revealed that the suicide rate has skyrocketed in the US in recent years, and that it has become the 10th leading cause of death in the nation. In 2016 alone, approximately 45,000 Americans died because of suicide. In 2017, the most recent year for which data is available, the number rose to 47,173.

Let that number sink in. In a single year, more than 47,173 people took their own lives. By comparison, AIDS took the lives of 50,628 Americans at the height of the epidemic in 1995. Meanwhile, it is estimated that more than approximately 42,000 women will die of breast cancer this year.

Before one can take clear steps to resolve a problem, however, one must understand it. Unfortunately, the reason for the spike in suicides is not entirely clear, nor is it likely to be due to a single factor or even a cluster of related factors even though rates rose between 2008 and 2017 for both men and women and in all age groups. For younger Americans, it is possible that the rise in suicide rates is due to social isolation, social media, and bullying. For middle-aged Americans, it is possible that the rise is linked to economic insecurity, opioid addiction, or social exclusion. Still other conditions would likely affect seniors.

It would seem wrong to assume that there is one proverbial silver bullet that can address all these issues, as different groups of Americans face different social and environmental factors that can affect suicide rates. However, one underlying issue that especially affects Americans with mental illnesses may be the lack of appropriate mental health services and resources, with data suggesting that there is a significant increase in suicide among patients post-discharge. Writing in 2005, Qin and Nordentoft found that, when compared to healthy controls, patients in the week following discharge had a markedly higher risk of suicide—102 times higher for men and 246 times higher for women.

While suicide can be linked to severe and persistent mental illnesses (SPMI) like major depression, bipolar disorder, and schizophrenia, it is also associated with personality disorders. Though not conventionally thought of as an SPMI, borderline personality disorder may also be considered an SPMI due to its enduring and lifelong impact.

What Is the Difference Between a Mood Disorder and a Personality Disorder?

When one thinks of mental illness, one mostly thinks of SPMIs. These mental illnesses arise due to a combination of neurobiological, genetic, and psychosocial factors. Historically, there has been a distinction between SPMIs and personality disorders. While SPMIs are recognized as disorders that have a strong genetic or neurobiological component, personality disorders have been believed to be primarily psychosocial. However, new data suggests that there may be a neurological element to these disorders that will be explored below.

DSM-5 defines personality disorders as being, “An enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual’s culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment.” A personality disorder is not merely a quirk or an eccentricity, nor is it a trait that comes and goes only in moments of extreme stress or duress. By their very nature, personality disorders are firmly established behaviors that persist even when such behaviors can have potentially dire circumstances.

The DSM-5 lists numerous personality disorders that are broken up into three primary clusters, as well as a miscellaneous cluster for other personality disorders that will be omitted here. The disorders that fall under the three clusters are:

  • Cluster A:
    • Paranoid Personality Disorder
    • Schizoid Personality Disorder
    • Schizotypal Personality Disorder
  • Cluster B:
    • Antisocial Personality Disorder
    • Borderline Personality Disorder
    • Histrionic Personality Disorder
    • Narcissistic Personality Disorder
  • Cluster C:
    • Avoidant Personality Disorder
    • Dependent Personality Disorder
    • Obsessive-Compulsive Personality Disorder

In many cases, a patient may have more than one personality disorder. Furthermore, some may also have a concurrent mood disorder or substance abuse disorder.  These comorbidities can put patients with personality disorders at an even greater risk of engaging in potentially dangerous behaviors.

Borderline Personality Disorder and Suicide

Of all the personality disorders listed above, data suggests that borderline personality disorder (BPD) has the strongest correlation with suicidal behavior. According to DSM-5, BPD is characterized by a “pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity that begins by early adulthood and is present in a variety of contexts.” Patients with BPD experience extreme distress when they sense impending rejection or abandonment, and oftentimes lash out at individuals for even minor perceived slights. They may also exhibit psychotic-like symptoms in times of extreme stress.

Yet another feature of BPD is a tendency for self-harm. DSM-5 notes that patients with BPD are prone to “recurrent suicidal behavior, gestures, or threats, or self-mutilating behavior.” Linehan and Heard, meanwhile, found that between 60% and 80% of patients with BPD engaged in parasuicidal behavior, and Joel Paris recently reasserted the findings of a study he coauthored in 2001 with Hallie Zweig-Frank, which concluded that completed suicide occurs in upwards of 10% of such individuals.

Patients with BPD are at an even greater risk of suicide if they have comorbidities like depression, substance abuse, or another personality disorder. Unfortunately, the latter two comorbidities are quite common. Nearly one quarter of patients with BPD also meet criteria for antisocial personality disorder, while both alcohol use disorder and drug use disorder are even more common—they affect 50% and 40% of patients with BPD, respectively. As upwards of two thirds of individuals who commit suicide had a diagnosable substance use disorder, it is clear that this is a major concern.

When all of these factors are taken into consideration, it reinforces the notion put forward by Apter et al, which is that there are two distinct impetuses that antecede suicidal behavior. The first is associated with depression and the desire to die. The second, which seems more appropriate among patients with BDP, is associated with aggression and impetuousness. It is more of a desire to escape in the moment without fully considering the consequences of one’s actions.

The Neurobiology of Borderline Personality Disorder

The neurobiology of personality disorders—and BPD in particular—must be understood in the context of developmental and psychosocial factors. Personalities develop due to a convergence of factors, and new data suggests that there may be specific predispositions and neurochemical abnormalities that influence personality disorders more than previously thought.

For example, part of the criteria for BPD is aggressive and impulsive behavior. While environmental and psychosocial components play a strong role in reinforcing these behaviors, evidence indicates that the serotonergic and dopaminergic systems within the brains of patients with BPD differ from healthy controls, thereby making it more difficult for them to control impulses.

Researchers have found additional differences in the brains of individuals with BPD when compared with healthy controls. Paul Soloff of the University of Pittsburgh, in particular, has pioneered several studies that have examined how BPD corresponds to volumes of gray matter in specific parts of the brain associated with impulsivity, aggression, emotional regulation, and episodic memory. Writing in the Journal of Psychiatric Research in 2012, he and his team report that, “MRI studies in BPD subjects compared to healthy controls report volume loss and diminished gray matter concentrations in areas of the frontal lobes, including orbital frontal cortex, and anterior cingulate cortex, in areas of the medial temporal lobes, including hippocampus, and amygdala.”

Even more intriguing, these findings not only indicated disparities in gray matter volume among patients with BPD and healthy controls; they also found disparities within the BPD group. “We found significant differences in gray matter concentrations between BPD attempters and non-attempters, high and low lethality attempters, suggesting a possible role for specific neural circuits in suicidal behavior. Affected areas include orbital frontal, temporal, insular and paralimbic structures, broadly involved in emotion regulation, behavioral control, executive cognitive function and adaptive responding in social situations  This suggests that there are structural differences not only between patients with BPD and controls, but between patients with BPD who attempt suicide and those who do not, as well as between high and low lethality attempters.”These studies do not suggest that the behaviors of patients with BPD are solely a function of a brain abnormality or pathology. Rather, they suggest that there may be neurological underpinnings on top of the psychological and social factors that predispose individuals to certain personality disorders like BPD. Furthermore, these studies indicate that comprehensive treatment of personality disorders like BPD require the consideration of the psychological, social, environmental, and neurological components that give rise to the disorder.

Though it is difficult to suggest clinical applications for these findings, it does potentially open the door to further studies that will allow us to better understand how BPD affects patients’ ability to mediate their most dangerous impulses. By understanding the mechanisms of the disorder better, we can hope to discover more effective means of treatment that will ultimately save lives.

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