Living in a damp and moldy house can contribute to depression independently of other personal and housing characteristics.
Based on a study of almost 6,000 adults living in eight European cities, researchers found that dampness and mold in a home is associated with elevated risk of depression. The heightened risk seemed to be due to a combination of physical health problems from exposure to mold and a perceived lack of control over the housing environment.
The study is the largest investigation of an association between mold and mood and is the first such investigation conducted outside the United Kingdom and is a statistical analysis of data from the Large Analysis and Review of European Housing and Health Status (LARES), a survey on housing, health and place of residence conducted in 2002 and 2003 by the World Health Organization (WHO).
To conduct the survey, WHO interviewers visited thousands of homes in eight European cities and asked residents a series of questions, including if they had depressive symptoms such as decreased appetite, low self-esteem, and sleep disturbances. WHO interviewers also made visual checks of each household, looking for spots on walls and ceilings that indicate mold.
Edmond Shenassa, the study's lead author and an associate professor in the Department of Community Health at Brown University, Providence, Rhode Island, said the findings came as a complete surprise. In fact, after a few U.K. studies published in the last decade had suggested a link, Shenassa and his skeptical team set out to debunk the notion that any link existed.
"We thought that once we statistically accounted for factors that could clearly contribute to depression - things like employment status and crowding - we would see any link vanish," he said. "But the opposite was true. We found a solid association between depression and living in a damp, moldy home."
However, the study does not prove that moldy homes cause depression. The study wasn't designed to draw that direct conclusion. But the research team did find a connection, one likely driven by two factors. One factor is a perceived lack of control over the housing environment. The other is mold-related health problems such as wheezing, fatigue and a cold or throat illness.
"Physical health, and perceptions of control, are linked with an elevated risk for depression," Shenassa said, "and that makes sense. If you are sick from mold, and feel you can't get rid of it, it may affect your mental health."
The study's authors said their findings underscore "the importance of housing conditions as determinants of mental health and the importance of housing as a medium for universal health promotion efforts." They suggested more study into the issue to determine if the increased risk for depression was directly related to moldy and damp surroundings.
Shenassa said that given the results of the current study, he wouldn't be surprised if there is a cause-and-effect association. Molds are toxins, and some research has indicated that these toxins can affect the nervous system or the immune system or impede the function of the frontal cortex, the part of the brain that plays a part in impulse control, memory, problem solving, sexual behavior, socialization and spontaneity.
Shenassa ED, Daskalakis C, Liebhaber A, Braubach M, MaryJean Brown MJ. Dampness and Mold in the Home and Depression: An Examination of Mold-Related Illness and Perceived Control of One's Home as Possible Depression Pathways AJPH 2007 Aug 29;doi:10.2105/AJPH.2006.093773 [Abstract]