The Body’s Missing Signals: How Interoception Breaks Down in Borderline Personality Disorder

For decades, research into borderline personality disorder has focused on the mind: the unstable moods, the fractured sense of self, the turbulent relationships that define one of psychiatry’s most misunderstood conditions. A growing body of evidence, however, suggests that to understand this disorder, scientists may also need to look below the neck. A new study published in Translational Psychiatry examines how people with borderline personality disorder perceive signals arising from within their own bodies—a capacity known as interoception—and finds that these impairments are not general but strikingly selective, and that they may shift meaningfully in response to treatment.

Interoception refers to the sensing of internal bodily states: the heartbeat pounding in the chest, the tightness of a full stomach, the heaviness of breath during anxiety. Far from being a passive background process, interoception is now understood as a foundation of emotional experience. Prominent neuroscientific theories propose that emotions are, at their core, the brain’s interpretations of bodily signals, and that the brain continually generates predictions about the body’s internal condition, updating them against incoming sensory evidence. When this predictive machinery misfires, the reasoning goes, emotional life can become distorted in ways that resemble psychiatric symptoms.

Borderline personality disorder, characterized by emotion dysregulation, impulsivity, chronic feelings of emptiness and an unstable self-image, has long been hypothesized to involve altered interoception. Clinical observations lend intuitive support: many patients describe feeling detached from their bodies, unsure whether they are hungry or full, numb or distressed. Previous studies, however, have produced inconsistent results, with some reporting impaired heartbeat perception in patients and others finding no difference from healthy controls. The new research tackles this inconsistency by treating interoception not as a single faculty but as a set of distinct dimensions that can be selectively affected.

This dimensional approach is technically important. Contemporary interoception research distinguishes between several separable components. Interoceptive accuracy measures how well a person can actually detect internal signals, most commonly the heartbeat, in tasks such as counting heartbeats without taking a pulse. Interoceptive sensibility captures a person’s self-reported beliefs about their bodily awareness, typically assessed with questionnaires. Interoceptive awareness reflects the metacognitive match between the two—whether someone’s confidence in their bodily perceptions corresponds to their actual performance. A person might be poor at detecting their heartbeat yet entirely confident, or accurate yet full of doubt, and these profiles carry different psychological implications.

Applying this framework, the researchers assessed a group of individuals diagnosed with borderline personality disorder alongside matched healthy comparison participants, using a battery of behavioral tasks, self-report instruments and metacognitive analyses. The results revealed a pattern of impairment that was selective rather than global. Patients did not show a uniform deficit across all facets of interoception. Instead, particular components—most notably certain aspects of cardiac signal detection and the metacognitive calibration of bodily confidence—were disrupted, while other facets remained relatively intact. This selectivity, the authors argue, may explain why earlier studies seemed to contradict one another: depending on which dimension a study happened to measure, it could find impairment or normal performance in the same population.

The specificity of the deficit is more than a methodological footnote. Different interoceptive channels and dimensions are thought to map onto different aspects of emotional and self-related processing. Cardiac interoception, in particular, has been linked to the experience of emotion intensity and to the brain’s ability to attribute arousal to its proper source. Difficulties in accurately reading cardiac signals, or in knowing when one’s bodily judgments can be trusted, could plausibly contribute to the emotional storms and unstable self-experience characteristic of the disorder. A person whose internal alarm signals are garbled may misread minor stress as catastrophe, or fail to register escalating distress until it erupts into impulsive action.

Crucially, the study did not stop at diagnosis. Because a subset of patients was assessed in relation to clinical treatment, the researchers were able to ask whether interoceptive function changes as symptoms improve. The findings suggest that treatment is associated with measurable shifts in interoceptive performance, hinting that the body’s signaling systems are not fixed features of the disorder but dynamic processes that can be reshaped. This has immediate translational appeal. If specific interoceptive impairments track symptom severity or recovery, they could serve as objective biomarkers—measurable indicators that complement the self-reports and clinical interviews on which psychiatric diagnosis currently depends.

The implications extend to therapy design as well. Existing frontline treatments for borderline personality disorder, including dialectical behavior therapy and mentalization-based approaches, already incorporate attention to bodily states, for example through mindfulness exercises that direct patients toward physical sensations. The new results suggest that such components may be more than auxiliary techniques; they may directly target mechanisms central to the illness. More speculatively, interoception-focused interventions—heartbeat tracking training, biofeedback, body-oriented psychotherapies—could be tailored to the specific deficits a patient exhibits, in the same way that rehabilitation after brain injury is matched to a patient’s particular cognitive profile.

Neuroimaging work by other groups provides a plausible biological substrate for these findings. Brain regions including the anterior insula, the posterior insula and the anterior cingulate cortex form a network that integrates visceral signals with cognitive and emotional context, and structural and functional anomalies in this network have been reported in borderline personality disorder. The selective pattern observed behaviorally in the new study is consistent with the idea that distinct nodes of this interoceptive network compute distinct things—the insula mapping bodily state, cingulate regions linking it to motivation and distress—and that damage or dysregulation at particular nodes produces particular symptoms rather than a general bodily numbness.

The researchers are careful to note the limitations inherent in this line of work. Cardiac tasks measure only one interoceptive channel among many, and heartbeat detection performance is influenced by factors ranging from body mass index to task strategy. Questionnaire-based sensibility measures can diverge from actual performance in ways that are themselves informative but difficult to interpret. Larger longitudinal cohorts will be needed to determine whether interoceptive deficits precede the onset of borderline symptoms, whether they predict treatment response, and whether deliberately training interoception produces durable clinical gains. Still, the study marks a conceptual shift: it reframes a disorder often described in purely psychological terms as one that involves measurable, treatable alterations in how the brain reads the body, opening a research agenda in which psychiatry and systems neuroscience converge on the question of what it feels like, at the most fundamental level, to be inside one’s own skin.

Subject of Research: Selective impairments in interoception and their relationship to treatment in borderline personality disorder

Article Title: Selective interoception impairments and treatment effects in borderline personality disorder

Article References: Voelter, J., Postin, D., Müller, C., Roheger, M., Schulz, A., Bekrater-Bodmann, R., Hurlemann, R., & Scheele, D. (2026). Selective interoception impairments and treatment effects in borderline personality disorder. Translational Psychiatry, 16(1), Article 463. https://doi.org/10.1038/s41398-026-04414-7

Image Credits: AI Generated

DOI: 10.1038/s41398-026-04414-7

Keywords: borderline personality disorder, interoception, heartbeat perception, emotion dysregulation, translational psychiatry, metacognition, body awareness, treatment effects, insula, biomarkers, Selective, impairments