Risk of suicide in association with major depressive disorder among patients with dementia: a populationbased nested...

This study aimed to explore the association between major depressive disorder (MDD) and suicide risk in patients with dementia.

A cohort of 625,218 individuals aged = 40 years with dementia was identified from Taiwan's National Health Insurance Research Database (NHIRD) between 2007 and 2018. After excluding prevalent cases in 2007, a nested case-control study enrolling 1,256 suicide cases and 5,022 matched controls was conducted. The frequencies of MDD-related outpatient or inpatient visits over a 7-year period preceding the event dates were calculated and analyzed for association using conditional logistic regression.

Dementia comorbid with MDD was associated with increased suicide risk (adjusted OR [AOR]: 2.67), particularly in individuals with = 1.0 MDD episodes per year (AOR: 2.85). A similar association was observed only in individuals aged = 65 years and males, with a pronounced risk of suicide in those experiencing = 1.0 MDD episodes per year (AOR: 3.08 for individuals aged = 65 years; AOR: 3.28 for males). Conversely, the risk increase was evident with > 1.0 MDD episodes per year in those aged < 65 years (AOR: 3.04) and females (AOR: 2.45).

MDD is associated with suicide risk in patients with dementia. The strength of this association possibly varies with age and gender.