Human brain illustration with hormone biochemical (serotonin, dopamine, and norepinephrine) concept background

Image courtesy of iStock Photo.

Dopamine, a chemical acting as a neurotransmitter, is responsible for sending thousands of little “messages” that ultimately make up our thoughts and actions. It has a myriad of functions within the body and brain, but it is best known for allowing us to feel pleasure, satisfaction, and motivation. Given this, it is no surprise that it becomes the point of focus when discussing addiction and reward. Social factors are also known to heavily influence the human brain and psychiatric outcomes, although there is scarce research proving a biological connection. As such, leading researchers at Yale have set out to explore these connections.

In this project, led by Katina Calakos and Aleksandra Rusowicz, the team used Positron Emission Tomography (PET scans) to image dopamine receptor (D2/3 R) availability. This data was obtained from previous studies and then correlated to population and socio-economic measures obtained from the Social Explorer Analyses of the 2014-2018 Census. The results were surprising. For one, they found that higher D2/3R availability was significantly associated with a higher total population in residential ZIP codes. Similarly, in zip codes where a lower percentage of the population possessed a bachelor’s degree or higher, there was a higher dopamine D2/3 R availability. Functionally, we can take this to mean that environment does have a significant impact on our brain chemistry – as evidenced by the changes seen throughout this study. 

Dopamine in and of itself is extremely useful, and as previously mentioned, necessary for normal bodily functions. However, issues can arise in cases of too much or little. For example, excess dopamine activity has been linked to anxiety, insomnia, and mania, while on the other end of the spectrum, low dopamine activity can cause issues like muscular issues, cognitive impairment, and attention deficits. Given this and the findings from this research, we can safely assume that the environment does impact the way your brain works, and this can then manifest itself in a plethora of ways.

When speaking to Aleksandra Rusowicz and David Matuskey, co-first author and senior author for this paper respectively, we discussed both the inspiration and the implications of this research and what it could mean going forward. This project was driven by prior animal studies focusing on how dopamine availability was affected by the animal’s position within its “society,” and how that could later predispose them to develop drug dependency. Initially, this team was asking questions focused on how greenspaces could affect brain chemistry, as environmental surroundings have been shown to affect brain activation. All those contexts came together to produce the research we are discussing today. 

Their findings represent one small step in filling the gap that is all too common for health research. Most of the evidence comes from epidemiological or longitudinal studies focusing on certain aspects of a population– living conditions, education, health, and correlations. However, the biological data to back-up these findings is simply scarce and a relatively new area of focus. This is why research like this could help inform future findings that focus even more closely on the type of social factors that impact social development. In addition, they expressed their hope that research like this could potentially have future policy implications, providing a biological backbone to diversity and education initiatives in communities that are often “tossed aside” or ignored. 

While Matuskey described the use of census data as “advantageous” in a way because they were able to focus on surroundings and environments, their research had some limitations. One of which was their use of this data. Despite how useful it was in gaining insight into these communities, it was fairly broad and could be considered outdated when we take into account the changes brought about by newer factors such as the COVID-19 pandemic. It is likely that if this team had had access to more specific data, we could have been able to discern even more detailed patterns about how location and social circumstances impact the brain developments in question.

To conclude, social factors have been correlated to health for years, but thus far we have lacked the biological data to support this claim. Thanks to researchers like these we now have biological data that can support the existing studies. As this type of science gains more traction, we will begin seeing more and more detailed results and maybe one day we can use those findings to push for policy change that ameliorates the roots of these problems.