People who live in damp, moldy homes may be prone to depression, a new study suggests.
The possible link was uncovered in an analysis of mold and health conditions in several cities in eastern and western Europe. And it could one day lead to the addition of emotional problems to the list of health woes caused by mold, the study authors said.
But, the researchers cautioned, it's still too soon to tell if exposure to mold is directly related to depression, or whether an already depressed person might simply relinquish control of their surroundings to the degree that mold may develop.
"There is some preliminary evidence which suggests that high levels of exposure to mold may lead to depression," said study lead author Edmond D. Shenassa, an assistant professor of community health at Brown University School of Medicine.
The study results are published in the October issue of the American Journal of Public Health.
Molds are ubiquitous and toxic microscopic organisms called fungi that come in a variety of species numbering in the tens -- or even hundreds -- of thousands. Mold spores -- spread through air, water or insects -- are found year-round both indoors and out, and survive and multiply most readily in warm, damp, shady, and humid conditions, according to the U.S. Centers for Disease Control and Prevention.
Typically, routine cleaning with soap, water and bleach can prevent mold from accumulating in the most susceptible areas, such as the seal of a refrigerator door, showers, windows, and air conditioners.
But, a serious mold problem -- easily evidenced by either the smell of a musty odor or the sighting of slimy, furry and discolored patches on walls or ceilings -- can develop and fester after excessive and continuous water damage.
The U.S. government has not established general guidelines for acceptable levels of residential mold. And no study has conclusively linked mold exposure to mental health problems.
However, the CDC cautions that inhaling living or even dead mold spores can provoke an allergic respiratory reaction among sensitive individuals. Wheezing, shortness of breath, and even lung infections can ensue, as can the onset of a stuffy nose, cough, headaches, and skin, throat, or eye irritations.
Those most at risk include men and women suffering from allergies, asthma, or the immune suppression that accompanies HIV infection, chemotherapy treatment for cancer, and organ transplants.
To explore the possible link between mold and mental health problems, Shenassa and his colleagues reviewed World Health Organization data collected between 2002 and 2003 in eight European cities: Angers, France; Bonn, Germany; Bratislava, Slovakia; Budapest, Hungary; Ferreira do Alentejo, Portugal; Forli, Italy; Geneva, Switzerland; and Vilnius, Lithuania.
Almost 6,000 men and women in almost 3,000 households were questioned in person about their health, including whether they had been clinically diagnosed as depressed in the prior 12 months. The participants, who ranged in age from 18 to 104, were divided equally between men and women and were chosen by random.
They were asked if they had experienced any of four symptoms of depression in the previous two weeks, such as problems sleeping, low self-esteem, poor appetite, or a decreased interest in activities. Those with three or more symptoms were deemed to be depressed.
Residents were also asked to assess their living conditions, while, at the same time, the researchers conducted visual inspections to calculate the levels and location of any dampness and mold in each home.
Finally, each study participant was asked whether or not they felt in control of their home environment, as well as whether they had any of six conditions that can be associated with exposure to mold, including: cold or throat problems; wheezing; asthmatic attacks or other respiratory problems, fatigue; or headaches.
Housing characteristics -- such as light, ventilation, size, crowding and heating conditions -- were also noted, as were basic demographic information such as employment status. The researchers pointed out that such factors, as well as general health, are sometimes associated with depression.
