No one likes mold. Yet the unsightly blight is present in an estimated 40 percent of American homes. And those rates may be higher in flood-ravaged areas like the Gulf Coast. The tiny fungi can irritate the upper-respiratory tract, causing coughing, wheezing and asthma symptoms in the 5 percent of the population with allergic antibodies to them.
But the effects of mold may be even more diverse than previously thought. A new study out this week in the American Journal of Public Health suggests that damp, moldy homes are associated with an increased incidence of depression. Why? "Some molds are toxins, and exposure to these toxins may hypoactivate parts of the brain that deal with emotions," says lead author Edmond Shenassa, assistant professor of epidemiology at Brown Medical School in Providence, R.I.
Shenassa and his colleagues looked at World Health Organization data from 5,882 adults living in eight cities in Europe, including Budapest, Geneva and Bonn, Germany. WHO interviewers asked residents if they had depressive symptoms such as decreased appetite, low self-esteem and sleep disturbances. Researchers found that those that said yes were more likely to live in damp, moldy homes. "[The study] suggests that healthy homes can lead to healthier lives. The take-home message is that housing conditions can influence health," says Shenassa. While the study did not provide a definitive reason for the link, study authors said that two factors are likely to be at play. One is the perceived lack of control over one's environment that mold can create and the other is mold-related health problems such as wheezing, fatigue and colds. (The team is conducting follow-up research to see whether mold directly causes depression.)
Not all the experts agree that there is any connection between mold and depression—despite this new research. Critics wish the study hadn't relied on self reports. "Having professionals do the inspection and rate homes for dampness or moldiness is much better than having people self report," says Pat Breysse, director of the division of environmental health engineering at the Johns Hopkins School of Public Health. Often people "point fingers at mold," but "the biological link between mold and a neurotoxic effect that might lead to depression is very tenuous, in my opinion," says Breysse.
But whether mold is linked to depression or not, many health professionals agree that homeowners need to fix their houses. The presence of mold doesn't just mean trouble for allergy sufferers, it also means a home is more likely to be infested with cockroaches, and it usually brings down property values.
So don't wait for an inspector, advises Breysse. "If you've got a leaky pipe and a big stain in the ceiling, you don't need to hire someone to say there's a big problem," he says. "It's an indication that the plumbing is leaking, the roof is leaking and the upkeep of the house is bad. Bad housing is not healthy for lots of reasons. That should be the message, not that mold causes depression."
To prevent the spread of the icky fungi, Shenassa recommends that you keep the bathroom and the kitchen as dry as possible and have space where one can get behind appliances to wipe out the water. He also suggests insulating around pipes, windows and maintaining good ventilation. After all, a dry home is likely to be a healthier home, even if it's not necessarily happier.