After studying a nationally representative dataset of more than 10,000 households, University of Chile researchers have identified a link between increased household density and symptoms of depression in Latin America.

Their findings, published May 24 in Social Science & Medicine, indicated that an increase in the number of people per bedroom in a particular household correlated with elevated symptoms of depression. The magnitude of the effect was high, comparable to that of being unemployed or of having a chronic illness. Yet people who experienced a reduced or constant household density over time saw no change in depressive symptoms. 

"The asymmetrical nature of our results highlights the relevance of preventive housing policies to confront overcrowding," the authors noted in the study.

The new findings could guide housing policies as well as future construction projects, helping governments balance the risk of overcrowding with other factors, such as housing affordability and access. 

Study co-author Ignacio Urria developed the project as a master's student in economic analysis at the University of Chile. He was inspired to explore the issue of overcrowding while working with TECHO, a nongovernmental organization that addresses extreme poverty in Latin America. Urria spent time with people in Chile's low-income social condominium developments. 

"I had the chance to talk to a lot of people living there, and there was this feeling of vulnerability — but not only in [terms of] income," he told The Academic Times. Residents did not just face stigma for living in a lower income community; they also frequently contended with overcrowding within their own residences, Urria said. 

"I want to make a little contribution to the discussion of how we can make this better — how we can solve this problem," he added.

The researchers calculated the density of a home by dividing its total occupancy by its number of bedrooms. The longitudinal housing data was gathered from the Chilean Social Protection Survey between 2006 and 2009. The 2009 survey included a brief section that evaluated participants' depressive symptoms, allowing the researchers to identify the cumulative effects of household-density changes on depression over the span of three years. In addition, the team sought to "control for psychological, health, environmental, family, employment and socioeconomic factors." 

The correlation between symptoms of depression and household density may stem from the living conditions associated with overcrowding. Those challenges include limited privacy and control over one's environment, less personal space and fewer opportunities to pursue private activities. And it was important to study households in Latin America, Urria said, so that researchers could better establish whether cultural or political factors shape the relationship between depression and overcrowding. 

"It's important to check whether this correlation observed in other regions of the world was also present [in Chile]," he noted. Urria added that future studies could also consider how overcrowding affects migrant populations, who often face higher levels of social and economic precarity.

The team dealt with several limitations, the largest of which was the inability to ascertain whether changes in household density stemmed from a move to an entirely new geographical location. In those cases, changes in one's environmental surroundings and neighborhood quality could have altered the results. For instance, due to the highly segregated nature of Chile's social housing, people who face overcrowding may seek a more spacious living environment by moving into a more isolated neighborhood with fewer resources, resulting in less substantial psychological benefits. 

The researchers emphasized, however, that "residential mobility in Chile is relatively low" — and they noted that the government offers subsidies for adding new bedrooms to an existing dwelling, which could also account for some of the changes in the number of bedrooms.

Although Urria's work began before the coronavirus pandemic, it took on a new urgency amid strict lockdown measures in Chile, when people in overcrowded households had less opportunity to leave their homes. The economic hardship that coincided with the pandemic also may have led extended families who had previously been living apart to move in together, potentially worsening the overcrowding issues noted in the study. Those negative effects also may have compounded over the length of quarantine; it has now been well over a year since the pandemic first affected Chile. 

Urria pointed out the ways in which the density of an entire neighborhood — not just a single household — might additionally contribute to negative mental health outcomes. Chile has made impressive strides to provide more housing to lower-income families, but its housing policies have sometimes created overcrowded areas of Chilean cities that remain segregated from the rest of the community. 

Urria described one neighborhood in Santiago, with around 30,000 inhabitants, that could only be accessed via a single entrance, further isolating its many residents from the rest of the urban area. The neighborhood also lacked its own fire and police departments, further heightening its vulnerability. 

Urria admits that it might not be beneficial or practical to demolish existing low-income housing infrastructure to build new apartment complexes. Instead, governments could focus on integrating businesses and cultural institutions closer to social housing developments in order to help connect those developments with the surrounding communities. 

"It's very difficult to change the whole structure of the city," he said. "But I think it's easier to [adjust] where the economic activity and the social activity are happening." 

Urria thinks policymakers should talk with people who live in overcrowded environments about what changes they would like to see before implementing any sweeping measures. 

"I think it's important to [ask], 'What are the needs of these communities?'" he said. "They have a big identification with their own neighborhood, so they know better."

The study "Household overcrowding trajectories and mental well-being" published May 24 in Social Science & Medicine, was authored by Jaime Ruiz-Tagle and Ignacio Urria, University of Chile.