Cities and neighborhoods with rat infestations should consider focusing on finding effective ways to control the rodent population, especially after a new study linked living with rats to an increased rate of depressive symptoms.

"Nobody likes living around rats," said study leader Danielle German, an assistant professor in the Department of Health, Behavior and Society at the Johns Hopkins Bloomberg School of Public Health. "This study provides very strong evidence that rats are an underappreciated stressor that affects how people feel about their lives in low-income neighborhoods. The good news is it's modifiable. If we can do something to reduce the number of rats in these neighborhoods, we can improve people's well-being."

Researchers at the Bloomberg School gathered data on 448 people who lived in low-income neighborhoods in Baltimore to assess depressive symptoms, such as anxiety. The sample was made up of mainly African-Americans and men with low incomes.

Overall, around 50 percent of the participants said they saw a rat on their block and 13 percent said they saw one inside of their homes on a weekly basis. The number of people who saw rats on a daily basis was slightly lower: 35 percent reported seeing rats on their block and 5 percent reported seeing them in their homes every day.

The researchers found that people who thought rats were a huge problem for their neighborhood were 72 percent more likely to have acute depressive symptoms in comparison to people who lived in similar areas but did not have as big of a rat problem. People who lived in rat-infested neighborhoods also had negative perceptions about rats that were similar to people who did not live in these neighborhoods.

"Those who live in areas where the perceived rat problem is the greatest are more pessimistic about their own ability to control rats, have less confidence in their neighbors' commitment to rat eradication and have relatively little faith that the city would act if called upon to address the rat problem," German said.

German added that even though eliminating or controlling the rat population can be a challenging task, city officials should work with its residents and try to handle the situation.

The study was published in the Journal of Community Psychology.