🌍 Oct 12: Who is still missing? Structural inequities and brain health in Parkinson’s research

Ideas and Inspiration
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I wanted to bring this topic to our community today because October 12 carries different meanings across the Americas. In the US, it is Columbus Day, marking Christopher Columbus’s arrival in the Americas in 1492. Across Latin America, the date is observed under different names, including Día de la Nación Pluricultural (formerly Día de la Raza) and, in countries such as Venezuela and Nicaragua, Día de la Resistencia Indígena. Increasingly, it has also become an opportunity to reflect on colonialism and its ongoing legacies. :globe_showing_europe_africa:

That reflection feels relevant to how we approach research.

One of GP2’s goals, supported by dedicated working groups, is to include populations historically underrepresented in research. This matters because our findings are not necessarily one-size-fits-all: genetic findings, risk factors, and clinical trajectories observed in one population may not translate directly to another. Studying more diverse populations helps us better understand this variation and work toward more equitable, individualized care.

But this raises another question: if we recognize the importance of studying populations historically left out of research, shouldn’t we also ask who remains underrepresented within those populations?

The Global South is not a homogeneous population. Neither are Indigenous communities in Canada or the United States, whose health and research experiences have been shaped by distinct histories of colonization, apartheid, ethnic cleansing, dispossession, racism, displacement, and constraints on self-determination. These histories are not interchangeable, but they remind us that broad population labels can conceal meaningful differences in lived experience, access to care, health outcomes and, overall, equity in health.

Research on Indigenous brain health highlights how colonial structures can affect health while also emphasizing the protective roles of cultural continuity, Indigenous knowledge, and self-determination (Henderson et al., 2024). Other contexts illustrate how structural violence can shape the conditions in which brain health develops and is maintained. In Gaza, for example, a study of 400 internally displaced adults reported extremely high levels of self-reported symptoms of depression (99.5%), anxiety (99.7%), and stress (93.7%) during G-cide (Albelbeisi et al., 2025). A narrative review also describes the broader psychosocial consequences of displacement, loss, and the disruption of family and community networks (Aqtam, 2025).

These findings do not establish the long-term neurological consequences of these experiences, and they should not be treated as direct evidence about Parkinson’s disease. I’m not concluding that. However, they raise important questions. What might prolonged psychological distress, disrupted education, loss of social support, and sustained barriers to healthcare mean for cognitive health over time? How might trauma and chronic stress intersect with other biological and social determinants of brain health? For many affected populations, answering these questions will require sustained, culturally appropriate, and longitudinal research.

What does this mean for Parkinson’s research?

I think it brings us back to some practical questions:

  • Who is missing from our datasets, and why? Recruitment, access to diagnosis, eligibility criteria, geography, and retention can systematically shape who is represented.

  • What do our categories hide? Broad labels such as Latino, African, Asian, or Indigenous can obscure meaningful differences in ancestry, culture, socioeconomic conditions, and lived experience.

  • What belongs in our analyses? Where relevant and supported by the study design, structural and social determinants—such as access to healthcare, socioeconomic conditions, environmental exposures, discrimination, and educational opportunities—may need to be considered alongside biological factors. Their relationships with outcomes may also warrant dedicated longitudinal investigation.

  • How do we interpret population differences? Genetic ancestry, social identity, and lived experience are not interchangeable. Genetic associations and polygenic risk scores should not be treated as straightforward explanations for health disparities.

  • Whose knowledge shapes the research? Meaningful community involvement in study design, consent, data governance, interpretation, and communication can help make research more relevant and accountable.

:warning: There is a cycle here worth paying attention to. Structural inequities shape people’s circumstances and opportunities for health; those circumstances may influence the outcomes we observe. If our studies overlook these conditions—or systematically fail to include the people most affected—we risk producing incomplete explanations and evidence that does not serve those populations well. That, in turn, can reinforce the gaps we hoped our research would help address.

:balance_scale: This is why acknowledging structural inequities is not just about adding context to the discussion section. It is also an ethical responsibility: to examine potential sources of systematic bias, account for relevant factors when methodologically appropriate, and contribute evidence that helps us understand how these conditions may influence brain health over time. No single study can address every determinant, and statistical adjustment alone cannot resolve structural inequity. But our research questions, methods, and interpretation can either overlook these realities or begin to account for them.

If our goal is to make Parkinson’s research more representative and equitable, perhaps we should keep asking not only whom we have managed to include, but also whose experiences remain unseen—and how that affects what we think we know.

A question for our community: As we broaden representation in Parkinson’s research, how can we better identify the people and experiences still overlooked within those broader groups, and incorporate the relevant structural determinants into both our scientific questions and our research practices?

References

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Thanks for this post, Ana! Your post raises crucial questions about representation that I think researchers like myself who come from historically privileged backgrounds need to keep confronting.

I agree the answer starts with centring community-led priorities in study design and funding decisions, rather than assuming we know which determinants matter most.

Can you share whether and how you are approaching these difficult questions in your own work with GP2? :slight_smile:

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Hello Ana, you have touched upon some very interesting topics that I find highly relevant today. I am Ramiro, from Bogotá. Since you have opened up this space, I would like to share that I am an independent researcher who has had the good fortune of discovering the true structure and function of the human brain—and I am not exaggerating. This was made possible through an innovative methodology involving a multidisciplinary team with expertise in psychology, anatomy, physiology, pathology, electronics, and mathematics. It began with the discovery of the “Functional Unit of the Brain”—a trio of neurons positioned in a specific configuration relative to one another, which generates a binary code (a “bit”) at each synaptic station within the nervous system. I have already published a book titled New Paradigms in Neuroscience (Nuevos Paradigmas en Neurociencias), which is available via Lulu.com, Amazon.com, and through a Spanish academic publisher, among other outlets. We are not only underrepresented in terms of healthcare attention, but also regarding our potential to contribute and provide solutions. I am hopeful that you might be able to help these solutions find a place within the community—and beyond. It would be a great help to us, and would also offer a significant contribution to the community at large. Kind regards.