Dementia in Africa: Current evidence, knowledge gaps, and future directions.

In tandem with the ever-increasing aging population in low and middle-income countries, the burden of dementia is rising on the African continent. Dementia prevalence varies from 2.3% to 20.0% and incidence rates are 13.3 per 1000 person-years with increasing mortality in parts of rapidly transforming Africa. Differences in nutrition, cardiovascular factors, comorbidities, infections, mortality, and detection likely contribute to lower incidence. Alzheimer's disease, vascular dementia, and human immunodeficiency virus/acquired immunodeficiency syndrome-associated neurocognitive disorders are the most common dementia subtypes. Comprehensive longitudinal studies with robust methodology and regional coverage would provide more reliable information. The apolipoprotein E (APOE) ε4 allele is most studied but has shown differential effects within African ancestry compared to Caucasian. More candidate gene and genome-wide association studies are needed to relate to dementia phenotypes. Validated culture-sensitive cognitive tools not influenced by education and language differences are critically needed for implementation across multidisciplinary groupings such as the proposed African Dementia Consortium.

Prevalence and associated factors of depression among older adults in rural Tanzania.

OBJECTIVES: Depression is the commonest mental disorder in older adults worldwide, affecting 7% of the world's older population and accounting for 5.7% of years lived with disability among adults aged over 60 years. We conducted a secondary data analysis to determine the point prevalence, associated risk factors and treatment gap for DSM-IV depression among older adults in the Hai District, rural Tanzania. METHODS: The primary data source was a cross-sectional two-stage community-based dementia study where older adults aged ≥70 years (n = 296) were fully-assessed for dementia and depression in the second stage. Age-adjusted prevalence of depression was determined based on the WHO standard population using the Direct Method. Univariate and multivariate logistic regression models were performed. RESULTS: Of the 296 older adults assessed for depression, 48 were diagnosed with depression based on Diagnostic and Statistical Manual of Mental Disorders-IV criteria. The median (Inter Quartile Range; QR) age was 80 (75-88) years. Age-adjusted point prevalence of depression was 21.2% (95% CI: 16.6-21.9) and the treatment gap for depression was 100%. There was reduced odds of depression in older adults who rated their physical health as good or very good (adjusted odds ratio [AOR] = 0.22; 95%CI: 0.10-0.46; p < 0.001), or moderate (AOR 0.26; 95%CI: 0.10-0.66; p = 0.005). CONCLUSIONS: Depression in older adults is associated with physical health status and there is an alarmingly high treatment gap. Future research on depression in older adults should focus on effective interventions to address physical morbidity, psychosocial factors and the treatment gap.