Comparisons of psychiatric diagnoses, medication prescription patterns, and psychiatric care utilization in first-degree relatives and spouses of individuals with and without Borderline Personality Disorder

OBJECTIVE: Small-scale studies have shown that the next-of-kin of individuals with Borderline Personality Disorder (BPD) face elevated risk of symptoms of mental illness. Little is known about whether these increased symptoms correspond to psychiatric disorders. The aim of this study was to examine the risk of psychiatric disorders, use of psychotropic medication, and utilization of psychiatric care in the next-of-kin of individuals with BPD. METHODS: Individuals diagnosed with BPD in Sweden, from 2011-01-01 to 2022-12-31, were matched (1:3) by age and sex to individuals without BPD. The study and control cohorts comprised the first-degree relatives and spouses of individuals with BPD and matched controls (n = 24,769 vs n = 77,728). Cox proportional hazards and Poisson regression models assessed associations between having a next-of-kin with BPD and outcome measures during five years post index. RESULTS: After adjustment for potential confounders, the next-of-kin in the BPD cohort exhibited an increased risk of any of the included disorders (HR 2.08; 95% CI 1.94-2.24), as well as higher rates of psychiatric care utilization (IRR 2.21; 95% CI 2.13-2.29), including inpatient care (IRR 2.23; 95% CI 2.02-2.47), and psychotropic medication use (HR 1.75; 95% CI 1.65-1.85), compared with the next-of-kin in the control cohort. CONCLUSION: In this nationwide study, the next-of-kin of individuals with BPD exhibited increased risk of psychiatric disorders, higher use of psychotropic medication, and greater utilization of psychiatric care. This study highlights the need of adequate care for individuals with BPD and emphasizes the importance of providing support to their next-of-kin.