Determinants of suicidal behavior in dementia: A Swedish national register-based study.

ABSTRACT

OBJECTIVES: To examine predictors of suicidal behavior (SB) in adults aged 75 years and above with dementia. DESIGN: Longitudinal national register-based study. PARTICIPANTS AND SETTING: Swedish residents aged ≥75 years with dementia identified in the Swedish Dementia Registry (SveDem) between 1 January 2007 and 31 December 2017 (N = 59 042) and followed until 31 December 2018. Data were linked with numerous national registers using personal identity numbers. MEASUREMENTS Outcomes were nonfatal self-harm and suicide. Fine and Gray regression models were used to investigate demographics, comorbidities, and psychoactive medications associated with fatal and nonfatal SB. RESULTS: Suicidal behavior was observed in 160 persons after dementia diagnosis; 29 of these died by suicide. Adjusted sub-hazard ratio (aSHRs) for SB was increased in those who had a previous episode of self-harm (aSHR = 14.42; 95% confidence interval [CI] = 7.06-29.46), those with serious depression (aSHR = 4.33, 95%CI = 2.94-6.4), and in those born outside Sweden (aSHR = 1.53; 95% CI = 1.03-2.27). Use of hypnotics or anxiolytics was also associated with a higher risk of SB; use of antidepressants was not. Milder dementia and higher frailty score also increased risk of SB. Risk was decreased in those who received home care (aSHR = 0.52; 95%CI = 0.38-0.71) and in the oldest group (aSHR = 0.35; 95%CI = 0.25-0.49). CONCLUSION: In addition to established targets for suicidal behavior prevention (improved identification and treatment of depression and previous self-harm), several new risk factors were suggested. There is a need for innovative public health strategies to meet the needs of older dementia patients with a foreign background. Home care may have a potential positive effect to prevent SB in people with dementia, but this needs to be further explored.