A new study suggests excessive emotional reactions can characterize adults with borderline personality disorder (BPD).

NIMH-funded researchers discovered adults with borderline personality disorder displayed extreme reactions when looking at words with unpleasant meanings compared to healthy people during an emotionally stimulating task.

They also found that people with more severe borderline personality disorder showed a greater difference in emotional responding compared to people with less severe BPD. The study was published in the journal Biological Psychiatry.

Borderline personality disorder is a serious mental illness characterized by intense fear of abandonment and/or rejection, problems controlling emotions, troubled relationships, impulsive or reckless behaviors, and other symptoms.

The disorder affects roughly 1.4 percent of adults ages 18 and older in the United States.

Erin Hazlett, Ph.D., of the Mount Sinai School of Medicine, and colleagues measured the startle eyeblink response, a measure of emotional reactivity, in 27 people with BPD and 21 healthy people.

Past research shows that people are generally more startled during unpleasant situations than during emotionally neutral ones.

During the study, each participant was shown a random series of words, some with neutral emotional meaning (such as “collect,” “regular,” “actually”) and some with unpleasant meanings, particularly for people with BPD (such as “hate,” “lonely,” “abandon”).

The participants would hear a brief startling burst of static noise at unpredictable intervals — sometimes while a word was shown, sometimes between words, and sometimes not at all.

The researchers found that both groups of participants had similar startle reactions when viewing neutral words. But people with BPD were more startled than healthy adults by the static burst when looking at unpleasant words.

Also, people with more BPD symptoms showed a greater difference in startle reaction when viewing unpleasant words vs. neutral words compared to people with less severe BPD.

This finding suggests that unstable emotions and impulsiveness in people with BPD may be related to an exaggerated startle reflex.

The researchers’ study presents an objective way to measure the problems with mood and emotional responses that are hallmark symptoms of BPD, suggesting a potentially useful adjunct to self-reported information when diagnosing and treating the disorder.

Source: National Institute of Mental Health