Study shows Narcissistic Personality Disorder may have a biological component

A study led by University of Chicago Medicine psychiatrist and personality disorder specialist Royce Lee, MD, finds that Narcissistic Personality Disorder (NPD) is marked by increased oxidative stress in the blood and is also connected to interpersonal hypersensitivity.

NPD is an often misunderstood mental condition where a person acts arrogantly, lacks empathy, needs constant attention and admiration, and has an inflated sense of self.

There are no FDA-approved treatments for NPD or any other personality disorders. Psychiatrists use psychotherapy, but the often-stigmatized personality disorder is a challenging condition to treat in part because so little is known about its biology. This study is a rare attempt to look at NPD’s biological mechanisms.

Oxidative stress is a molecular imbalance between antioxidants and free radicals, or reactive oxygen molecules in the body. The imbalance creates stress on the body because it must metabolize excessive oxidative chemicals that go to the brain and throughout the body.

The study, “Narcissistic and Borderline Personality Disorder: Relationship with Oxidative Stress,” published in March in the Journal of Personality Disorders, found that elevated concentrations of the molecule called 8-OH-DG, an oxidative stress biomarker, were similar in people with NPD and Borderline Personality Disorder (BPD).

The finding was interesting, given how differently the disorders present themselves outwardly. For example, people with NPD have extremely high self-esteem, and people with BPD exhibit very low self-esteem. Yet it appears they’re biologically related.

“There’s a tendency to assume they’re almost the opposite biologically, but I don’t think that’s true now,” Lee said. “This rise in oxidative stress levels may not be seen in all personality disorders. It was only seen in these two disorders in this study. That was a little surprising.”

Lee said it raises the question of which came first: the personality disorder, or the excessive oxidative stress?

Additionally, the study found that NPD represents a disorder of hypersensitivity. When dealing with interpersonal stress, someone with NPD might appear aloof on the outside. But on the inside, the study results suggest it’s actually hypersensitivity to the environment. That means there could be a possible relationship between oxidative stress and how people act on their emotions.

“We found that the levels of oxidative stress were related to impaired recognition or expression of shame. That’s interesting, because we know from previous research that people high in narcissism have problems with the emotion of shame. What we’re trying to figure out is the relationship between hypersensitivity and shame, and why that leads people to avoid empathy. This paper doesn’t quite get us there. That’s the next question,” Lee said.

Besides biological and behavioral factors, Lee also questioned if our modern-day culture can impact narcissism and increase metabolic stress on the body. The current social media and internet culture can impact how people interact and feel about themselves.

“Those factors can affect how much metabolic stress the body has to deal with,” Lee said.

While not many biology-based studies have been done on NPD, there have been some encouraging biological studies of BPD in recent years, opening the door for more brain-based NPD studies, Lee said.

“BPD went from an untreatable, so-called character disorder to a medical condition we now think of as highly treatable. NPD remains in this category of mysterious, stigmatized, misunderstood conditions. Clinicians aren’t sure what to do with it. In the science community, there’s been this renewed interest in trying to rehabilitate NPD. That’s what’s behind this paper,” Lee said.

The study “Narcissistic and Borderline Personality Disorder: Relationship with Oxidative Stress,” was co-authored by David Gozal, MD, MBA, from the University of Missouri School of Medicine’s Department of Child Health, Emil F. Coccaro, MD, from the University of Chicago Department of Psychiatry and Behavioral Neuroscience, and Jennifer Fanning from Harvard University, PhD, Harvard Medical Hospital’s Center for Depression, Anxiety and Stress.