Factors Associated with Suicidal Ideation Among Middle-Aged Korean Adults: A Cross-Sectional Analysis of the 2022–2023 Korea National Health and Nutrition Examination Survey

Background/Objectives: Suicide became the leading cause of death among Korean adults in their 40s in 2024. We identified sociodemographic, health behavior, and mental health correlates of suicidal ideation in mid-life without adjustment for depression, which overlaps with the outcome through Patient Health Questionnaire-9 item 9 and was measured in only one of the two survey years. Methods: This cross-sectional secondary analysis of the 9th Korea National Health and Nutrition Examination Survey (2022–2023) used complete data from 4715 of 5153 adults aged 40–64 years. Anxiety symptoms were assessed with the Generalized Anxiety Disorder-7 scale (screening threshold ≥ 10). Complex-sample logistic regression incorporated strata, clusters, and pooled weights, with all covariates prespecified. Results: Suicidal ideation prevalence was 3.8%. Independent correlates were high perceived stress (odds ratio (OR) = 8.54, 95% confidence interval (CI) 5.47–13.34), one-generation other-type household (OR = 6.81, 3.29–14.08; n = 59, 11 events), elevated anxiety symptoms (OR = 5.01, 3.02–8.32), middle school education or below (OR = 2.13, 1.12–4.03), economic inactivity (OR = 1.85, 1.25–2.73), poor perceived health (OR = 1.70, 1.13–2.55), and low household income (OR = 1.57, 1.08–2.28). Wave-specific adjustment for depression attenuated the stress and anxiety associations by 15–55% without eliminating them. Conclusions: Mid-life suicidal ideation was associated with mental health vulnerability, household composition, and socioeconomic disadvantage. The value of these cross-sectional associations for screening or risk stratification requires prospective evaluation.