Introduction
Alzheimer's disease (AD) is the leading cause of dementia in the elderly and involves pathophysiological events which results in progressive cognitive impairment and functional disabilities. Loneliness is a unique condition in which an individual perceives themselves as socially isolated, even when they are among other people. It is also a worldwide public health challenge associated with higher mortality, and risk of cardiovascular and psychiatric diseases. The aim of this study is to investigate the impacts of loneliness on the development of AD in women.

Methods
Systematic Review registered in PROSPERO (CDCRD42024521068) and adherent to PRISMA and Cochrane guidelines. In November 2025, systematic searches conducted by independent reviewers were carried out in international databases. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale and the Downs and Black Checklist.

Results
A significant association is suggested between loneliness and the development of AD. Possible causal mechanisms were identified, namely chronic stress associated with loneliness, lack of social and emotional support, and reduced cognitive and social activity. The organization of studies allows for an analysis of the incidence of AD, the progression of cognitive decline, and the relationship with neurobiological changes associated with loneliness.

Conclusion
Despite being a complex and barely understood relationship, Loneliness may play a relevant role in the development of AD among women. Psychosocial factors must be considered in the context of aging and women's mental health, emphasizing its role in increasing the risk and progression of the disease.