Key points Is there an association between a dementia diagnosis and an increased risk of suicide? Findings In this nationally representative case-control study that included 594,674 people in England from 2001 to 2019, dementia was found to be associated with an increased risk of suicide in specific subgroups of patients: those diagnosed before age 65 (particularly in the 3 months after diagnosis), those in the first 3 months after diagnosis, and those with known psychiatric comorbidities. Meaning Given current efforts to improve dementia diagnosis rates, these findings emphasize the importance of simultaneous implementation of suicide risk assessment for identified high-risk groups. |
Importance
Patients with dementia may be at increased risk of suicide. Identification of groups at highest risk of suicide would support targeted risk reduction efforts by clinical dementia services.
Goals
To examine the association between a dementia diagnosis and suicide risk in the general population and identify high-risk subgroups.
Design, environment and participants
This was a population-based case-control study in England conducted from 1 January 2001 to 31 December 2019. Data were obtained from multiple linked electronic records from primary care, secondary care and the Office of Statistics Nationals.
Included participants were all patients aged 15 years or older and registered with the Office for National Statistics England with a death coded as suicide or open verdict from 2001 to 2019. Up to 40 living control participants per suicide case were randomly matched in primary care practice and date of suicide
Exhibitions
Patients with codes referring to a diagnosis of dementia were identified in the primary and secondary care databases.
Main results and measures
Odds ratios (ORs) were calculated using conditional logistic regression and adjusted for sex and age at the index/suicide date.
Results
Of the total sample of 594,674 patients, 580,159 (97.6%) were controls (median [IQR] age at death, 81.6 [72.0-88.4] years; 289,769 male patients [50, 0%]), and 14,515 (2.4%) died by suicide (median [IQR] age at death, 47.4 [36.0-59.7] years; 10,850 male patients [74.8%] ]).
Among those who died by suicide, 95 patients (1.9%) had a recorded diagnosis of dementia (median [IQR] age at death, 79.5 [67.1-85.5] years; median [IQR] duration of follow-up, 2.3 [1.0-4.4] years).
There was no overall significant association between a dementia diagnosis and suicide risk (adjusted OR, 1.05; 95% CI, 0.85-1.29). However, the risk of suicide was significantly increased in patients diagnosed with dementia before age 65 (adjusted OR, 2.82; 95% CI, 1.84-4.33), in the first 3 months after diagnosis (OR adjusted, 2.47; 95% CI, 1.49- 4.09), and in patients with dementia and psychiatric comorbidity (adjusted OR, 1.52; 95% CI, 1.21-1.93).
In patients under 65 years of age and within 3 months of diagnosis, the risk of suicide was 6.69 times (95% CI, 1.49-30.12) higher than in patients without dementia.
Conclusions and relevance
Dementia diagnosis and treatment services, in both primary and secondary care settings, should target suicide risk assessment to identified high-risk groups.
