Association between the presence of the E4 allele of Apolipoprotein E (APOE4) and depressive symptoms in cognitively healthy older adults and with mild cognitive impairment.

• Grant number: 25/14185-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Medicine - Psychiatry
• Principal Investigator: Márcia Regina Cominetti
• Grantee: Maria Clara Ribeiro Zucato
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Population aging is a global phenomenon that presents significant challenges for public health-particularly in Brazil, where the elderly population is growing at an accelerated rate. Research has shown that depressive disorders are prevalent among older adults and are associated with an increased risk of developing dementia, including Alzheimer's disease (AD). Apolipoprotein E (APOE) plays a key role in lipoprotein metabolism and cholesterol transport in the body. The presence of at least one ¿4 allele of the APOE gene (APOE4) is a well-established risk factor for AD. However, despite the known association between APOE4 and AD, its relationship with depressive symptoms remains unclear, especially within the Brazilian population. This study aims to investigate the potential association between the APOE4 allele and depressive symptoms in cognitively healthy older adults and those with mild cognitive impairment. A cross-sectional, observational design with quantitative methods will be employed. Participants will be categorized into groups based on the presence or absence of the ¿4 allele and depressive symptoms, as assessed by the 15-item Geriatric Depression Scale (GDS-15). Cognitive assessments and genetic testing will be conducted to determine participants' cognitive status and APOE genotype. Statistical analyses will include group comparisons and association tests. The findings of this study may enhance our understanding of how genetic factors interact with depressive symptoms in aging populations, contributing valuable insights for the development of preventive and management strategies for chronic non-communicable diseases such as dementia, within the broader context of global population aging.