BioEd Online

A national survey of US citizens has found that 6% of them have a debilitating mental illness.

More startling, almost half of those surveyed were found to have had a mental disorder at some point during their lives; more than a quarter had had one in the year before the interview.

The researchers involved say they also found that treatment is hard to get, and often not sufficient when available. They estimate that only about a third of those in care receive "minimally adequate treatment", such as the appropriate drugs or a few hours of therapy over a period of several months.

Four papers reporting the results appear in the Archives of General Psychiatry this week¹,²,³,⁴.

The statistics are nearly impossible to compare with previous studies, thanks to constantly changing definitions of mental illness, the researchers say. But in general, they add, things don't seem to have changed much over the past decade.

Home visits

More than 9,000 US adults, chosen randomly, were visited in their homes as part of the National Comorbidity Survey, which looks at the incidence of multiple mental disorders. An interview then probed to see whether they had mental difficulties as determined by the latest Diagnostic and Statistical Manual of Mental Disorders, a guide used by psychiatrists. The study also classified the severity of disorders, separating them into severe, moderate or mild conditions.

The definition of disorders used by the study was quite broad. A few instances of road rage, for example, might qualify as an "intermittent explosive disorder". Such a wide net may not be any use in determining who needs medication or treatment, says Thomas Insel, head of the National Institute of Mental Health and co-author of a commentary on the results.

But the survey does provide some useful information, Insel adds. It reveals, for example, that 50% of those with a mental disorder encountered problems before their 14th birthday. This indicates that watching for signs of mental distress in early years could help to avert larger problems in the future.

Insel hopes that progress will be made in finding biological markers that can help distinguish children who are simply shy or have a quick temper from those whose difficulties are likely to degenerate into illness. Perhaps this could be done through an analysis of genes or brain scans, he suggests.

Meanwhile, the first order of business is to improve the quality of treatment, he says. "We're just not delivering care," says Insel.