Mind and Metabolism in Crisis: US Mortality Involving Obesity and Psychiatric Disorders-Trends, Disparities, and ARIMA Projections.

Background: Obesity and psychiatric disorders are major contributors to morbidity and premature mortality in the US and frequently co-occur, yet their joint mortality burden has not been systematically quantified nationally. Methods: We conducted a retrospective population-based study of adults aged ≥25 years using the CDC WONDER Multiple Cause of Death database (1999-2023). Deaths were identified using ICD-10 codes for obesity (E66) and psychiatric disorders (F01-F99). Age-adjusted mortality rates (AAMRs) were calculated, and trends were assessed using joinpoint regression to estimate annual percent change (APC). Future trends through 2030 were forecasted using autoregressive integrated moving average (ARIMA) modeling. Sociodemographic and geographic disparities were examined using multivariable Poisson regression, reporting incidence rate ratios (IRRs). Results: A total of 195,180 deaths were identified. AAMRs increased from 6.0 to 82.2 per million between 1999-2021, then declined to 66.6 per million in 2023. The steepest increases occurred in 1999-2005 (APC=+19.2%) and 2018-2021 (APC=+20.6%). Substance use disorders showed the highest burden (AAMR=29.8), followed by mood (2.6), organic (2.2), and psychotic (1.0) disorders. Mortality was higher in males (IRR=1.41) and adults aged 65-74 years (IRR=8.34). Per-capita mortality was highest among American Indian/Alaska Native populations and lowest among Asian individuals (IRR=0.09). ARIMA projected a rebound to 74.2 per million by 2030. Conclusion: Co-occurring obesity and psychiatric disorders are associated with rising and inequitable mortality in the US, underscoring the need for integrated obesity care, metabolic monitoring, and targeted substance use interventions.