Hospital-Diagnosed Dementia and Suicide: A Longitudinal Study Using Prospective, Nationwide Register Data

Abstract

Objective-The current study aims to examine the risk of suicide in persons diagnosed with dementia during a hospitalization and its relationship to mood disorders.Design-Event-history analysis using time-varying covariates. Setting-Population-based record linkage.Participants-All individuals aged 50+ living in Denmark (N = 2,474,767) during January 1, 1990 through December 31, 2000. Measurements-Outcome of interest is suicide. Relative risks are calculated based on persondays spent in each stratum.Results-A total of 18,648,875 person-years were observed during the 11-year study period. During this period, 136 persons who previously had been diagnosed with dementia died by suicide. Men and women aged 50-69 years with hospital presentations of dementia have a relative suicide risk of 8.5 (95% confidence interval: 6.3-11.3) and 10.8 (95% confidence interval: 7.4-15.7), respectively. Those who are aged 70 or older with dementia have a threefold higher risk than persons with no dementia. The time shortly after diagnosis is associated with an elevated suicide risk. The risk among persons with dementia remains significant when controlling for mood disorders. As many as 26% of the men and 14% of the women who died by suicide died within the first 3 months after being diagnosed whereas 38% of the men and 41% of the women died more than 3 years after initial dementia diagnosis.Conclusions-Dementia, determined during hospitalization, was associated with an elevated risk of suicide for older adults. Preventive measures should focus on suicidal ideation after initial diagnosis but also acknowledge that suicides can occur well after a dementia diagnosis has been established. KeywordsSuicide; dementia; Alzheimer disease; old age; elderly persons; Denmark Dementia is related to a substantial health care burden. 1 Worldwide, the prevalence rate of dementia is estimated to be 0.6%-1.9% among persons aged 65-69 years and 10%-33% Older adults also have high suicide frequencies and in many countries the highest suicide rates are found among the oldest old. 5 Thus far, the relationship between dementia and suicide has been assessed through case reports and clinical studies. Although case reports suggest that dementia might be associated with an increased risk of suicide, 6-10 clinical studies document lower risks among patients with dementia than other inpatients. 8,[11][12][13][14] Although attempted suicides are reported to be rare among inpatients with dementia, 15,16 a recent Chinese study found that more than 10% of demented inpatients had been admitted after a suicide attempt. 17 The prevalence rate of suicidal ideation is estimated to range between 0.9% and 42%. 12,18 Specific types of dementia, such as Huntington and Alzheimer diseases, are mentioned by case reports as potential predictors for suicidal behavior. 7,9,[18][19][20] Furthermore, early stages of dementia, 6,10,20 intact awareness of disease and its course, 6,[8][9][10]21 and accessibility to means 6,8 might increase the risk of suicide.Comorbid mental diso...

Issues in research on aging and suicide

“…However, cognitive changes play an important role in health and well-being in later life, and represent one domain in which risk factors for suicide in later life may differ from those of middle aged and younger adults, thus warranting attention. A prospective study using nationwide register data from Denmark found that a diagnosis of dementia made during hospitalization significantly increased risk for dying by suicide, even when controlling for mood disorders (Erlangsen, Zarit, & Conwell, 2008). Risk was highest during the first several months after the diagnosis of dementia was made, though for some, risk continued to be elevated years after the diagnosis.…”

Suicide in Older Adults: The Role of Emotions and Cognition

“…In a recent study of demented older adults in VA healthcare settings, there were 81 suicides per 100,000 subjects [29]. In a large longitudinal study in Denmark, adults aged 50–69 years old with dementia had an 8–10-fold higher risk of suicide than those without dementia, whereas the risk decreased in those aged 70 years old and older (3-fold higher suicide risk) [30]. In a study comparing patients with early semantic dementia (N=25) and those with Alzheimer’s Disease (N=111) [31], 5 patients with semantic dementia had suicidal behavior and two of those committed suicide, whereas only one patient with Alzheimer’s Disease attempted suicide but did not kill himself.…”

“…Suicide declines with increased cognitive impairment, but there are conflicting reports on whether recently diagnosed demented patients are at higher risk [30, 32–34]. The presence of a major depression in these patients may contribute to increased suicide risk [35].…”

“…There may be a certain phase of cognitive decline or a particular cognitive profile that predisposes one to suicidal behavior. For example, a Danish population study found a marked increase in suicide rates in dementia patients after an inpatient admission [30]. It is likely that age-related neurodegenerative and vascular changes [55, 56] modify older adults’ vulnerability to suicide.…”

Pathways to Late-Life Suicidal Behavior

“…There is a large body of evidence indicating that cognitive deficits are associated with suicidal thoughts and behavior 8, 9 . One pathway to suicide may thus be characterized by late-onset suicidal behavior where age-related cognitive decline or prodromal dementia 10-13 interact with dispositional and environmental factors. Another pathway maybe marked by decision-making deficits 14-16 seen in real life and in the laboratory in a subgroup of suicide attempters, accompanied by different levels of cognitive impairment 12, 15-21 and impulsivity.…”