People in low-income neighborhoods who believe that rats are a big problem in their area are highly likely to suffer from depressive symptoms such as anxiety and sadness, a new study in Baltimore, Maryland revealed.

The same people whose neighborhoods are plagued by rodents are also affected by other urban issues such as drug sales on the streets, vacant housing, the possibility of getting beaten up and the threat of being robbed. However, the study found that the link between the presence of rats and depression is not explained by these issues.

"Nobody likes living around rats," said study primary author Danielle German. But rats infest places where they have access to shelter and food. They find trash they could eat, and live in poorly-kept or vacant houses.

In fact, residents have felt the strong presence of rats in their blocks.

Each time researchers from the Johns Hopkins Bloomberg School of Public Health talked to residents of low-income neighborhoods about the issues they face, German said they had expected to hear about HIV, drugs, or the lack of access to healthy food.

But time and again, German and her colleague Carl Latkin heard about rats and trash.

The Link Between Depressive Symptoms And The Presence Of Rats

The duo analyzed data from 448 residents in Baltimore, all of whom were recruited from impoverished areas in March 2010 to December 2011. The original study was designed to reduce sex and drug risk behaviors by addressing symptoms of depression. About 87.3 percent of the participants were African-American, and 54.9 percent were male.

Half of the participants had reported seeing rats at least weekly on their block. Around 35 percent said they saw the rats every day. Approximately 13 percent said there were rats inside their homes, while 5 percent said they saw rats inside their homes daily. More than half of the participants believe that the presence of rats is a sign of a bad neighborhood.

Nearly 32 percent of the participants said rats were a big problem in their area. Of this group, 80 percent said they saw rats on the block daily, while 85 percent reported them lurking in the neighborhood.

German and Latkin found that those who consider the presence of rats to be a big problem were 72 percent more likely to experience acute depressive symptoms than those who don't. They also found that residents in rat-infested areas had strong negative perceptions of rats as people in other neighborhoods, but they had more frequent encounters with the pests.

Their findings offer firm evidence that rats are indeed underappreciated stressors that affect how people in low-income areas feel about their lives. It's also one of the first studies to assess the psychological implications of a neighborhood entrenched with rats.

Meanwhile, German said the conversation about rats has been framed into concerns about the pests being vectors for disease. However, she believes that it misses what it feels like to live in a neighborhood where there are rats visibly lurking around.

"There is no reason why rats should be inherent to areas of poverty," said German.

The Problem Of Infestation

Many cities in the United States have programs to reduce the population of rats, but the problem can be quite difficult to control.

For instance, Baltimore is currently undertaking efforts to give its residents a sturdy trash can to reduce the problem.

German said that may not be enough, especially because there are still issues of illegal dumping and vacant lots that are filled with garbage.

Still, she said the problem with rat infestation and its link to depression can be changed.

"If we can do something to reduce the number of rats in these neighborhoods, we can improve people's well-being," said German. "Yes, eradicating rats from Baltimore City is a hard goal, but making it so no neighborhood has to see rats every day is a goal we can strive for."

The findings of the study are featured in the Journal of Community Psychology.

Photo: Peter Pearson | Flickr