INTRODUCTION

Vulnerability means susceptibility to developing a physical or mental health problem due to marginalized sociocultural or socioeconomic status or individual characteristics (Kuran et al., 2020). Vulnerable populations at high risk of developing mental health problems include those with individual-level social determinants such as childhood adversities, sex-based inequalities, and inequalities experienced by the LGBTQ+ community (Kirkbride et al., 2024). Vulnerable groups have specific, often overlooked needs and encounter socio-economic barriers and limited access to health and education services. These factors interact, leading to an increase in the marginalization and vulnerability of those affected, taking a toll on their mental health (World Health Organization, 2010).

According to Kirkbride et al (2024), “social determinants of (mental) health represent the most modifiable set of targets for intervention currently available to prevent the onset of mental health problems and disorders, and to promote positive mental health in our populations” (p. 58). Nevertheless, further research is required to describe the problem, identify modifiable risk factors, and develop, adapt, and evaluate interventions to mitigate mental health challenges among vulnerable populations in low- and middle-income countries (LMICs). Most evidence in the field is available on high-income countries (HICs) in the Global North, and although some social determinants of mental health may be similar, others will differ in LMICs (World Health Organization, 2022).

This monothematic collection of articles brings together empirical quantitative and qualitative studies, as well as systematic reviews of risk factors and interventions to advance our knowledge of this issue. It also seeks to contribute to improving the mental health and wellbeing of those in the greatest need, particularly in Latin American countries.

Trauma as a risk factor and therapeutic target

A key issue in this collection is trauma, a major contributor to mental health inequalities (Kirkbride et al., 2024). Zhang et al., 2026 share their quantitative, cross-sectional evaluation of the complex, reciprocal relationship between acute and chronic stress exposure and psychopathology. Their study participants comprised a broad sample of young adults from a range of geographical and cultural contexts, including two Latin American countries (Chile and Mexico). Future longitudinal studies could further explore the temporal causal relationships and mechanisms of influence between stressors and psychopathology.

Regarding the evaluation of interventions in the field, Hernández Castrejón et al., 2026 conducted a feasibility study of online trauma-informed yoga for female Mexican primary informal caregivers of children under psychiatric treatment. This is particularly relevant given that, in Mexico and other similar countries, women are generally the primary informal caregivers of those in need in the family. It is a well-known fact that informal caregivers of psychiatric populations face a variety of challenges, increasing their risk of mental health problems.

Jiménez-Rivagorza et al., 2026 turned their attention to psychosocial interventions for the LGBTQ+ community. According to their systematic review, Affirmative Cognitive Behavioral Therapy achieved the greatest effect on trauma, depression and anxiety symptoms. However, only one of the 19 original articles included was from Latin America. Although support interventions targeting these specific populations may be pertinent as secondary prevention, rigorous evaluations of trauma-informed interventions are required in LMICs.

Gender-related barriers to access to treatment

Another key theme highlighted in this anthology is related to barriers to assessing health services for mental and physical problems among other highly marginalized subpopulations of women. Loría Alfaro et al., 2026 undertook a systematic review of treatment access barriers among women who use drugs. They found that, across global contexts, stigma, gender-specific (such as fear of losing child custody), structural (such as limited treatment availability), and psychosocial factors (such as lack of family or community support) discouraged treatment-seeking among these groups.

Toiber-Rodríguez et al., 2026 focused on Aging Mexican Women Living with HIV, who often face intersecting inequities limiting their access to HIV care. Using a qualitative approach, the authors explored the ways these women actively respond to the structural constraints on treatment they experience through self- and collective care practices, financial strategies, and re-authoring later life identities.

The findings of both studies call for the development, implementation and scientific evaluation of gender-responsive and community-based mental and physical treatment for women with mental and physical health problems.

CONCLUSIONS

This monothematic issue includes key studies on mental health and wellbeing in three vulnerable populations facing individual-level social determinants: young adults who have experienced childhood adversities, women in highly distressing and/or stigmatized conditions, and LGBTQ+ people experiencing minority distress. Study samples included participants from Latin American countries, thereby contributing to reducing the research gap in the field in this region. Two main topics emerged: trauma as a risk factor for mental health problems and as a relevant therapeutic outcome, and women’s barriers to mental and physical care. An analysis of the contributions and limitations of the studies could have a heuristic value for creating targeted, effective preventive and therapeutic interventions, and undertaking further research to advance this field.