Geriatric Suicide Attempt and Risk of Subsequent Dementia: A Nationwide Longitudinal Follow-up Study in Taiwan

Objective: It was unclear whether older people without dementia who attempted suicide were at increased risk of subsequently developing dementia. Methods: Using the Taiwan National Health Insurance Research Database, 1,189 patients aged >= 65 years who attempted suicide and 4,756 age-and sex-matched control subjects were enrolled in our study and followed to the end of 2011. Those who developed dementia during the follow-up were identified. Results: Cox regression analysis, after adjusting for demographic data and medical comorbidities, found that geriatric suicide attempt was associated with an increased risk of subsequent dementia (HR: 7.40; 95% CI: 6.11-8.97; Wald chi(2) = 414.87, df = 1, p < 0.001). Both patients aged between 65 and 79 years (HR: 7.74; 95% CI: 6.17-9.71; Wald chi(2) = 312.62, df = 1, p < 0.001) and patients aged >= 80 years (HR: 6.94; 95% CI: 4.73-10.17; Wald chi(2) = 97.78, df = 1, p < 0.001) who attempted suicide had an increased risk of developing dementia in later life. Conclusion: The elderly who attempted suicide were prone to developing dementia in later life, independent of depression and medical comorbidities. Further studies are necessary to clarify the underlying mechanisms between geriatric suicide and dementia and whether the prompt intervention for geriatric suicide may reduce this risk.