Abstract

Background:

Borderline personality disorder (BPD) is linked to a shorter life expectancy and poorer psychosocial functioning than seen in the general population, with outcomes comparable to those seen in schizophrenia. This is partly explained by the high prevalence of chronic physical illnesses.

Methods:

This study aimed to compare rates of multimorbidity and chronic illnesses in individuals with BPD, schizophrenia, and healthy controls, and to examine behavioral risk factors, such as impulsivity, sleep disturbances, and substance use, that may underlie physical health outcomes. We analyzed data from 590 adults enrolled in the Signature database, including validated health and behavioral measures.

Results:

Participants with BPD showed the highest rates of multimorbidity (49.4%) and were over four times more likely to report chronic illnesses than controls. Key risk factors associated with increased chronic disease burden included longer sleep latency, higher impulsivity, and smoking, while being a non-smoker was protective.

Conclusion:

These findings indicate that physical comorbidities and multimorbidity are at least as prevalent in individuals with BPD as in those with schizophrenia, with age and impulsivity emerging as key contributing factors. While the results underscore the potential value of integrating lifestyle medicine into clinical care, particularly by targeting sleep and substance use, further research is needed to elucidate the causal mechanisms underlying the interplay between BPD and multimorbidity.

1 Introduction

Individuals with severe mental illnesses, such as Borderline Personality Disorder (BPD) and schizophrenia, experience significantly poorer physical health outcomes, including higher rates of premature death, chronic diseases, and functional impairment (1, 2). Physical multimorbidity, defined as the co-occurrence of two or more chronic conditions (3), has emerged as a key measure of disease burden in this context. While BPD is primarily characterized by emotional and relational instability, impulsivity, and identity disturbance (4), growing evidence shows that individuals with BPD also face a marked reduction in life expectancy, with excess mortality from both suicide and physical illness (5, 6). Despite this, research has largely focused on psychiatric outcomes, neglecting the physical health dimension.

Contributing factors to this mortality gap include altered stress regulation due to childhood adversity and HPA-axis dysregulation (7, 8), along with behavioral risks such as impulsivity, substance use, and physical inactivity (9). A similar pattern is observed in schizophrenia, where shared mechanisms such as medication side effects, stigma, and health service disparities contribute to a life expectancy reduction of 12–15 years (10, 11). While both disorders exhibit overlapping vulnerabilities, such as impulsivity and emotional dysregulation, comparative studies on physical health outcomes are lacking.