Understanding Excess Mortality in Mental Disorders: A Nationwide Study

Excess Mortality in Mental Disorders: A Growing Concern

Excess mortality associated with mental disorders is a well-established issue, but estimates are often based on specialist psychiatric populations. According to editorial research analyzed by Groundwork, Whether these estimates accurately characterize mortality in the broader diagnosed population is uncertain. A recent nationwide population-based cohort study aimed to address this knowledge gap by examining heterogeneity in excess mortality across mental, behavioural, and neurodevelopmental disorders.

Study Design and Methods

The study employed a nationwide population-based cohort design with follow-up from January 1, 2011, through December 31, 2023. The study setting included primary and specialist health care and population registers in Finland. Participants were residents aged 5 to 95 years without a recorded prevalent mental disorder at cohort entry. The study exposures included mental, behavioural, and neurodevelopmental disorders classified using ICD-11, with time-varying psychiatric care setting and substance use disorder (SUD) status.

Key Findings

Among 5,526,599 individuals (2,784,897 [50.4%] women), 1,463,064 (26.5%) received a mental disorder diagnosis. Excess mortality varied substantially by diagnosis, clinical subgroup, and time since diagnosis. Among those aged 5 to 64 years with any mental disorder, adjusted mortality rate ratios (MRRs) across care setting and SUD strata ranged from 1.54 (95% CI, 1.39-1.71) to 8.97 (7.86-10.24). MRRs were highest immediately after first diagnosis and declined during the first 2 to 3 years.

Mortality Rate Ratios by Diagnosis and Time Since Diagnosis

Ten-Year Survival Loss Across Mental Disorders

Ten-year survival loss across all mental disorders was 0.53 years (95% CI, 0.53-0.54) in men and 0.34 years (0.33-0.34) in women. This loss was greater for natural than external causes.

Implications and Conclusion

Excess mortality varied markedly by diagnosis, clinical context, and time since diagnosis. Estimates derived from specialist psychiatric populations or averaged across follow-up may therefore provide an incomplete picture of mortality in the broader diagnosed population. This study highlights the importance of considering heterogeneity in excess mortality when developing strategies to address mental health disparities.