Mental health service use and suicide risk after a dementia diagnosis: a population-based retrospective matched cohort study

Objectives — To compare deaths due to suicide and mental health and addiction (MHA)-related health services utilization between adults with and without a new dementia diagnosis.

Method — This matched cohort study assessed all Ontarians aged 40–105 y with a new diagnosis of dementia between January 2013 and December 2018. Those without dementia were compared to those with dementia utilizing a 2:1 age-, sex- and region-match ratio. Dementia diagnoses were identified via a validated algorithm. Death by suicide, and MHA-related outpatient physician visits, emergency department (ED) visits, and hospitalizations within six months of diagnosis date or matched index date were compared between individuals with vs. without dementia.

Results — Our cohort included 504,709 individuals (33.4% with dementia). In the six months after diagnosis/matched index date, 24.3% of individuals with dementia had 1+ MHA-related outpatient visit compared to 7.8% in those without dementia. The adjusted rate of outpatient mental health visits was 2.52 times higher (95% confidence interval (CI): 2.50 − 2.55) in those with vs. without dementia. The risk of suicide was low and did not differ between groups.

Conclusion — Our findings suggest that a recent dementia diagnosis is associated with increased use of MHA-related health service use, particularly outpatient services.