TUESDAY, July 24, 2001 (HealthDayNews) -- If you feel city living is making you crazy, you're not alone.
A new study from the Netherlands suggests you're more at risk for a psychotic illness if you live in a city than if you live in a rural area.
Living in crowded conditions may cause social isolation, allowing abnormal ideas to progress into full-blown mental illnesses, such as schizophrenia, the researchers say. And they say brain development may be affected by the stress of growing up in a crowded environment, increasing the risk for psychotic illness.
"It is increasingly clear that urban life is associated with higher rates of physical and psychiatric illness," says Dr. Jan van Os, professor in the department of Psychiatry and Neuropsychology at Maastricht University. "We found in the Netherlands that urban upbringing and residence increased the odds of first hospital admission for schizophrenia [in earlier studies]. However, this may be caused by treatment being more readily available in the big cities. We therefore wished to replicate [these results] in an epidemiological study, interviewing a representative sample of the general population."
Van Os and his colleagues analyzed data on more than 7,000 people from 90 different municipalities in the Netherlands. They correlated diagnoses of psychotic disorders, frequency of delusions and hallucinations and such things as feelings of persecution with the population density of where subjects lived.
"What we found was that individuals living in urban areas are more likely to display mild psychosis-like symptoms that increase the risk of developing into full-blown psychotic illness," he says. "However, the majority of individuals with these mild symptoms will never become ill. It is just that the risk pool of slightly abnormal mental states that may progress to full-blown illness is much larger in the big cities."
The findings appear in the July issue of the Archives of General Psychiatry.
Loneliness could increase the risk for psychotic illness, van Os says: "Cognitive psychologists suspect that living in the big cities may give rise to higher levels of social isolation. This may be important with respect to psychosis, because one needs social interaction in order to remain 'sane.' Lack of social interaction may lead to failure to correct early paranoid or other abnormal ideas, allowing them to grow into full-blown illness."
"There are other possibilities, such as the greater exposure to psycho-social stress, which we know brings out latent psychosis in vulnerable individuals. And [there are] lower levels of interpersonal trust, which we know affects crime rates in deprived neighborhoods and may also affect levels of paranoia," he says.
"Developmental biologists suggest that brain development may be affected by the stresses of the great city in much the same way as animal brain development is affected by the quality of the environment they grow up in," he says.
An estimated 22.1 percent of Americans aged 18 and older, or about 44 million people, suffer from a mental disorder in any given year, reports the U.S. National Institute of Mental Health. About 2.2 American adults have been diagnosed with schizophrenia.
"It's a good study, but it's not necessarily a new finding," says Dr. John Talbott, professor of psychiatry at the University of Maryland in Baltimore. "People have noticed this as far back as Dickens and wondered why it is that cities, and especially dense inner cities, have a prevalence of people with serious psychotic illness."
"There are two prevailing theories," Talbott says. "One, called downward drift, essentially says that when you develop serious mental illness with a basic impairment to your ability to think, it is those people who have the most difficulty negotiating in urban areas. They wind up without jobs, without family, without community and 'drift down' so you wind up with a higher concentration of these kinds of problems in inner cities."
"The other prevailing theory is that people living in inner cities have higher exposure to crowding, to traffic, to pollution, to noise, to violence, to drugs, and that influences cognitive and psychiatric changes over the years," Talbott says.
Van Os says doctors and researchers should focus on the mechanisms in big cities that increase the risk for psychotic illness.
"We may have to look for treatments that reduce risk in entire populations, rather than focusing exclusively on individuals that are already sick," he says.
What To Do: For more information on psychosis, visit Helping Overcome Psychosis Early or MedSupport.
