Study; people who live in moldy environments are prone to more depression

The physical consequences (increased asthma and other respiratory ailments, headaches, fatigue, and sore throats . . .) of living in a damp, moldy house are well documented. A just released study of 5,882 adults living in 2,982 households, (October 2007, the American Journal of Public Health) found that people who live in moldy environments may also have more depression.

The connection between mold and mental health even surprised the lead author, epidemiologist Edmond Shenassa of Brown University, who was skeptical of the mold–depression link suggested by smaller studies. “We thought that once we statistically accounted for physical factors like crowding and psychological aspects like not having control over one’s living environment, then the association between mold and depression would vanish,” he says. But rather than debunking the notion, Shenassa found an association between mold toxins and depression.

Shenassa and colleagues analyzed data collected by the Large Analysis and Review of European Health Status, a survey of housing, health, and place of residence compiled by the WHO in 2002 and 2003. WHO interviewers visited households in eight European cities and asked residents about depressive symptoms, such as problems sleeping and decreased appetite. They also asked whether a physician had diagnosed depression in the past year. Then they measured the level of dampness and mold in each residence and classified any discernable mold exposure as minimal, moderate, or extensive.

About 40% of the residents lived in visibly damp, moldy households, and overall their risk for depression averaged 34–44% higher than that for residents of mold-free dwellings, with moderate exposure associated with the highest increase in risk. Shenassa says there may be a tipping point where a certain critical amount of mold triggers a response that is not dose-related.

The heightened depression risk also correlated to respondents’ perceptions that a damp, moldy environment cannot be controlled, as well as to documented physical health problems linked to mold exposure. “If you are sick from mold and feel you can’t get rid of it, it may affect your mental health,” says Shenassa, who is undertaking animal studies to investigate whether mold toxins alter behavioral and biochemical brain pathways involved in depression.

Robert Gifford, a psychology professor at the University of Victoria, British Columbia, interprets the results cautiously. Considering only the highest level of mold contamination, when both physical health and perception of control were factored in, the link between mold and depression shrank to “virtually nothing,” he says. However, at minimal and moderate mold exposure, even when controlling for both mediators, there still remained a statistically significant 28–34% higher risk, says Shenassa.

“There is a relationship between depression and mold and dampness, but it is impossible to say that there is a causal relationship,” Gifford says. In addition, more details about income should be explored—wealthier people can afford to clean up extensive mold contamination, whereas low-income people may be forced to live with it. “Income could be an important missing variable,” he notes.

Why is mold growing in my home?

Mold growing outdoors on firewood. Molds come in many colors; both white and black molds are shown here.

Molds are part of the natural environment.  Outdoors, molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees, but indoors, mold growth should be avoided.  Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air.  Mold may begin growing indoors when mold spores land on surfaces that are wet.  There are many types of mold, and none of them will grow without water or moisture.

Can mold cause health problems?

Molds gradually destroy the things they grow on. You can prevent damage to your home and furnishings, save money, and avoid potential health problems by controlling moisture and eliminating mold growth

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing.  Molds have the potential to cause health problems.  Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins).  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.  Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis).  Allergic reactions to mold are common.  They can be immediate or delayed.  Molds can also cause asthma attacks in people with asthma who are allergic to mold.  In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people.  Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold.  Research on mold and health effects is ongoing.  This brochure provides a brief overview; it does not describe all potential health effects related to mold exposure.  For more detailed information consult a health professional.  You may also wish to consult your state or local health department.

How do I get rid of mold?

  • The key to mold control is moisture control.
  • If mold is a problem in your home, you should clean up the mold promptly and fix the water problem.
  • It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.