Prevalence of physical comorbidities and multimorbidity in Borderline Personality Disorder: risk factors and comparisons with schizophrenia and healthy controls.

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.