The interplay between depressive symptoms, body mass index change patterns in adulthood, and all-cause mortality risk: a population-based study.

Background: Recent studies have suggested body mass index (BMI) change patterns in adulthood may be crucial for depression. This purpose of this study is to evaluate the impact of adult BMI change patterns on depression.

Methods: The National Health and Nutrition Examination Survey 2007 to 2018 generated the data. The relationships between adult BMI change patterns and depression / Patient Health Questionnaire 9 (PHQ-9) were investigated using logistic regression and generalized linear model with a Poisson distribution. The relationships between BMI change patterns, depressive symptoms, and all-cause mortality were examined by Cox proportional hazards models. Kaplan-Meier curves were employed to illustrate the cumulative incidence over time. To explore whether adult BMI change patterns mediate this link between depression and all-cause mortality, mediation analysis was conducted.

Results: A total of 10,448 participants were included, with 7.8% reporting depression. Significant differences were observed in demographic, lifestyle, and health characteristics across BMI change patterns. The high-increase pattern was linked to a1.61 times greater odds of depression after adjustment (odds ratio = 1.61, 95% confidence interval (CI): [1.16, 2.24], P = 0.006) compared to the non-overweight pattern. Gender and age differences were also observed. The higher PHQ-9 was correlated with increased all-cause mortality risk, even after adjustment (hazard ratio: 1.03; 95%CI: 1.02-1.05). Mediation analysis revealed that adult BMI change patterns mediated 26.98% of the correlation between depressive symptoms and all-cause mortality.

Conclusion: Persistent obesity in adulthood rises the risk of depression, and BMI change patterns playing a modest role in mediating the link between depressive symptoms and all-cause mortality. Early intervention in individuals at-risk BMI change patterns might reduce depression risk. Future research should investigate whether modifying BMI change patterns can lower depression incidence.

Clinical trial number: Not applicable.