Participants with severe depression showed a 27% higher likelihood of developing malignant glioma, based on hazard ratios from a recent study.
Researchers investigated the association between depression and the risk of malignant glioma (MG). Using data from the Korean National Health Insurance System, the researchers analyzed a population of 3,856,362 adults aged 20 years and older who underwent health check-ups in 2009. Participants with prior cancer diagnoses, incomplete data, or glioma diagnoses within one year of the index date were excluded to minimize bias.
Depression was identified using ICD-10 codes F32 and F33, while MG cases were identified using ICD-10 code C71. Participants were followed for an average of 10.14 years, with outcomes including MG onset and all-cause mortality. The researchers adjusted for potential confounders, including age, sex, income, body mass index, smoking, alcohol consumption, regular exercise, and comorbidities such as diabetes mellitus, hypertension, and dyslipidemia. Cumulative incidence was evaluated through Kaplan-Meier analysis, with group differences compared using the log-rank test. The Kaplan-Meier curves demonstrated a higher cumulative incidence of MG among participants with depression, with the risk increasing alongside depression severity.
Published in the Journal of Psychosomatic Research, the study demonstrated that depression was associated with a significant increase in MG risk. The crude hazard ratio (HR) was 1.753 (95% confidence interval [CI]: 1.588–1.935). Adjusting for age and sex reduced the HR to 1.225 (95% CI: 1.108–1.355). After full adjustment for confounders, the HR was 1.127 (95% CI: 1.101–1.347). A dose-response relationship was observed between depression severity and MG risk. Participants with less severe depression (diagnosed within five years but without active claims in the year of health check-up [Stage 1]) had an HR of 1.187 (95% CI: 1.049–1.343), whereas those with severe depression (diagnosed within five years and with active claims [Stage 2]) had an HR of 1.273 (95% CI: 1.089–1.491). (Refer to Table 2 for detailed HRs.)
Subgroup analyses showed consistent associations across sex and age groups, though socioeconomic and behavioral factors such as income, smoking, and exercise were less influential within the MG cohort. The researchers hypothesized that chronic neuroinflammation linked to depression, including elevated levels of cytokines such as tumor necrosis factor-alpha and interleukins, may contribute to glioma development.
The study highlights several limitations. First, the reliance on data from the Korean NHIS limits generalizability to other populations. Additionally, MG encompasses various subtypes, but this study did not differentiate between them. The diagnosis of depression relied on healthcare data, which may have resulted in underreporting. Despite these limitations, the findings suggest that the severity of depression plays a role in MG risk.
The study highlights the need to better understand the biological mechanisms underlying the depression-MG relationship and calls for further research into preventive and therapeutic strategies. For detailed statistical outcomes and cumulative incidence trends, refer to the Kaplan-Meier curves and Table 2 in the original publication.
Full disclosures can be found in the published study.