An investigation of neuropsychiatric symptoms, contextual factors, and antidepressant treatment as risk factors for dementia development in people with mild cognitive impairment

BackgroundWhile some people with mild cognitive impairment (MCI) progress to dementia, many others show no progression. The aim of this study was to identify factors associated with risk of dementia development in this population.MethodA large naturalistic retrospective cohort study was assembled from mental healthcare records in a south London catchment. Patients were selected at first recorded diagnosis of MCI and subsequent dementia diagnosis was ascertained from case notes or death certificate, excluding those with dementia diagnoses and deaths within 6 months of MCI diagnosis. A range of demographic and clinical characteristics were ascertained around MCI diagnosis and Cox proportional hazards models were used to investigate independent predictors of dementia, focussing on neuropsychiatric symptoms, contextual factors, and antidepressant treatment.ResultsOf 2250 patients with MCI, 236 (10.5%) developed dementia at least 6 months after MCI diagnosis. Aside from older age, lower cognitive function, and activities of daily living impairment, impaired social relationships and recorded loneliness were associated with a higher risk of developing dementia. Patients of Black (compared to White) ethnicity were at a lower risk. For depression and antidepressant receipt, only tricyclic use compared to no antidepressant use was associated with an increased dementia risk.ConclusionsNo evidence was found for co-morbid affective disorders or different antidepressant classes as risk factors for dementia development following MCI diagnosis, but loneliness and social impairment were independent predictors and would be worth evaluating as targets for interventions to delay progression. Of 2250 patients with MCI, 10.5% received a recorded dementia diagnosis at least 6 months after MCI diagnosis. Older age, lower cognitive function and impaired ADLs were associated with dementia development. Problems with social relationships and loneliness led to a higher risk of developing dementia. Affective disorder diagnoses, antidepressant treatment, and choice of antidepressant did not affect dementia risk.