When Brains Get Left Behind: Borderline Personality and Social Rejection Inscribed in the Rostromedial Frontal Cortex.

“Who among us.” doesn’t mind rejection? Feeling social rejection or exclusion is painful and distressing, especially when it is dispatched by someone we depend on. In the current issue of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, Fertuck et al. (1) suggest that the psychological significance of social rejection can be situated in the wider context of Maslow’s Theory of the Hierarchy of Needs (2). This enduring psychological model posits 4 fundamental social needs that motivate the range of human behavior: belonging, self-esteem, control, and meaningful existence. Social exclusion is seen as a direct threat to these needs, often leading to the subjective experience of rejection distress. In moderation, this distress can be considered adaptive, as it signals to those important others that the social bond needs affirmation or repair. Indeed, overt expressions of distress and behavioral consequences in response to ruptures of the social bond are readily observed in most highly social mammals [dog lovers see (3)]. When humans experience this response in an unstable manner, however, as noted below, considerable hazardous behavior can ensue, in ways that can be hard to predict and even harder to mitigate, and this is one of our greatest concerns as clinicians. We have learned in the modern era of cognitive neuroscience that responses to social rejection relate to the brain’s sensitive detection that things are not right, that what we have received from our environment has not matched our goals. Thus, regions in the medial frontal cortex relating to social rejection light up (as revealed during functional magnetic resonance imaging) as they do when we make errors, have expectations violated, or feel somatic pain (4,5). Luckily, much of the time (surely not always) the brakes get applied automatically; the brain’s tendency for operating homeostasis kicks in, allowing us to subvocalize “I can deal with this,” and we (or our observers) experience that as emotion regulation. Unfortunately for some of us, the experience of rejection has a destabilizing, chaos-generating effect, and this can lead to trouble for both ourselves and those around us. And if rejection-related trouble is a regular feature of one’s psychological functioning, that individual may receive a psychiatric diagnosis of borderline personality disorder (BPD). As Fertuck et al. (1) note, for persons with BPD, this can often lead to high-risk urges and behaviors, including self-harm, suicide attempts, and completed suicide (7). These responses to rejection are a hallmark of BPD as much as any other clinical feature, and yet we have had only a foggy idea about how this happens in the brain.