Depressive disorder and elevated risk of bell's palsy: a nationwide propensity score-weighting study

Prior studies have reported a potential relationship between depressive disorder (DD), immune function, and inflammatory response. Some studies have also confirmed the correlation between immune and inflammatory responses and Bell's palsy. Considering that the pathophysiology of these two diseases has several similarities, this study investigates if DD raises the risk of developing Bell's palsy.

This nationwide propensity score-weighting cohort study utilized Taiwan National Health Insurance data. 44,198 patients with DD were identified as the DD cohort and 1,433,650 adult subjects without DD were identified as the comparison cohort. The inverse probability of treatment weighting (IPTW) strategy was used to balance the differences of covariates between two groups. The 5-year incidence of Bell's palsy was evaluated using the Cox proportional-hazard model, presenting results in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).

The average age of DD patients was 48.3 ± 17.3 years, and 61.86% were female. After propensity score-weighting strategy, no significant demographic differences emerged between the DD and comparison cohort. The Cox proportional hazards model revealed a statistically significant adjusted IPTW-HR of 1.315 (95% CI: 1.168-1.481) for Bell's palsy in DD patients compared to comparison subjects. Further independent factors for Bell's palsy in this model were age (IPTW-HR: 1.012, 95% CI: 1.010-1.013, p < 0.0001), sex (IPTW-HR: 0.909, 95% CI: 0.869-0.952, p < 0.0001), hypertension (IPTW-HR: 1.268, 95% CI: 1.186-1.355, p < 0.0001), hyperlipidemia (IPTW-HR: 1.084, 95% CI: 1.001-1.173, p = 0.047), and diabetes (IPTW-HR: 1.513, 95% CI: 1.398-1.637, p < 0.0001) CONCLUSION: This Study confirmed that individuals with DD face an elevated risk of developing Bell's palsy. These findings hold significant implications for both clinicians and researchers, shedding light on the potential interplay between mental health and the risk of certain physical health outcomes.