People who live in disadvantaged areas are at greater risk for depression, according to a study led by researchers from the University of Washington School of Public Health.

“Depression is one of the biggest health problems, both globally and in the United States,” said lead author Hannah Cohen-Cline, who conducted the research as a doctoral student in the Department of Epidemiology at the University of Washington School of Public Health.

Aside from several known factors on the individual level that contribute to depression, there is growing recognition that neighborhood environment can also affect mental health. This study, published in the Journal of Epidemiology and Community Health, assessed the link between socioeconomic deprivation and depression among 7,476 twins. Each twin pair was raised together, but twins lived separately as adults. Twin samples control for confounding by shared genetic and environmental factors.

To measure neighborhood deprivation, researchers used the Singh Index, which combines 2010 census data on education, employment and income, as well as home, vehicle and telephone ownership. The higher the index score, the greater the socioeconomic deprivation, which represents the lack of social and economic benefits considered to be basic necessities in a certain community.

When comparing twins within a pair, a 10-unit difference in neighborhood socioeconomic deprivation was associated with 6 percent greater depressive symptoms.

“Policies that seek to reduce neighborhood deprivation could have a profound benefit on population mental health,” said Cohen-Cline, now a research scientist at Providence Health and Services in Portland, Oregon. This study provides new evidence linking neighborhood socioeconomic deprivation with greater depression. However, future studies using longitudinal designs are needed.

A neighborhood’s socioeconomic deprivation may lead to negative perceptions of that community’s quality as well as fear of crime and victimization. This may prevent residents from creating meaningful social ties. Deprivation can also influence the quality of neighborhood infrastructure and local amenities such as parks, recreation facilities and healthcare services.

This study used data from the Washington State Twin Registry, formerly the University of Washington Twin Registry. University of Washington co-authors include Shirley A.A. Beresford, professor of epidemiology and adjunct professor of health services; Wendy Barrington, assistant professor of psychosocial and community health and adjunct assistant professor of epidemiology; Ross Matsueda, professor of sociology; Jon Wakefield, professor of statistics and biostatistics; and Glen Duncan, affiliate professor of epidemiology.