NCDs and depression pose substantial public health challenges, particularly in urban-marginalized areas of low-to-middle-income countries (LMICs), where socioeconomic disparities amplify mental health concerns. The risk factors for NCDs among both younger and older adults in urban-marginalized areas of Latin America have been inadequately studied.

Our study investigates the prevalence and risk factors of neurocognitive disorders (NCDs) and depression among community-dwelling younger and older adults in Puente Piedra, an urban-marginalized district of Lima, Peru.

A population-based study was conducted from July through September 2022, incorporating door-to-door visits and structured questionnaires to collect demographic, health, and socioeconomic data from 900 community-dwelling adults aged 30 years and older. Neurocognitive assessments included the Addenbrooke's Cognitive Examination for younger adults, Rowland Universal Dementia Assessment Scale for older adults, and Patient Health Questionnaire (PHQ-9) for depression screening.

We found that 75.6% of participants were cognitively normal, 20.1% had possible NCD without functional impairment, and 4.2% with functional impairment. Additionally, 40% were depressed. After controlling for covariates, lower educational levels and lower socioeconomic levels were risk factors for NCD among older adults. Among younger adults, lower educational levels, a native language other than Spanish, hypertension, and depression were risk factors for NCD. Risk factors for depression included female sex, lower educational level, a native language other than Spanish, overcrowding in the home, and a history of chronic diseases.

Our results highlight that potentially modifiable risk factors, such as hypertension, educational level, and depression may play a role in NCDs among residents of an urban-marginalized area of Peru. These findings underscore the critical need for targeted interventions and policies to address mental health  and healthcare disparities in urban-marginalized areas of LMICs.