Mental disorders are becoming more common, often beginning in the teenage years and afflicting many sufferers for the rest of their lives, according to an international psychiatric study. Almost half of those who are ill don’t seek help, most are not treated at all, and often the treatment is inadequate – even though effective therapies exist, the research shows.

The findings are published in the latest issue of The Bulletin of the World Health Organization. The issue, dated April 2000, is devoted to mental health, and in an accompanying editorial, WHO’s Director-General Dr Gro Harlem Brundtland says: "Mental illness suddenly bulks very large indeed. All predictions are that the future will bring a dramatic increase in mental problems. It is a crisis of the 21st century."

The WHO International Consortium in Psychiatric Epidemiology examined data from 30 000 people in seven countries – Brazil, Canada, Germany, Mexico, the Netherlands, Turkey and the United States –Researchers found that 48% of those studied in the US experienced at least one disorder in their lifetime, compared to 40% in the Netherlands, 38% in Germany, 37% in Canada, 36% in Brazil, 20% in Mexico and 12% in Turkey.

Overall, the median age of onset for anxiety disorders was just 15 years, 21 years for substance use disorders and 26 years for mood disorders. Delays in seeking treatment were especially pervasive among people with early onset of symptoms. All three classes of illness were most common in disadvantaged sectors of society, and linked particularly to people with low income and below-average education, or who were unemployed or unmarried.

Anxiety disorders were most likely of the three to become chronic, and more common in women than men, as were mood disorders. Substance use disorders were more common among men.

"The proportion of the life course during which people with mental disorders are actively in [a mental disorder] episode is substantial", the researchers report.

"This substantial burden is especially important in the light of the fact that mental disorders often have a devastating effect on role functioning and quality of life.

"They also have powerful adverse effects on critical life course transitions such as educational attainment, teen childbearing, marital instability and violence."

The researchers add: "It is discouraging to find that the vast majority of recent cases, even those who report substantial impairment, are not in treatment". Whereas it is not yet known whether early treatment could prevent the adverse life course effects of mental disorders that have early onset, the researchers say it is "critically important" that early "outreach treatment" efforts are refined, implemented and evaluated.

In her editorial, Dr Brundtland says there are several reasons why effective treatment for disorders such as depression is not provided. "The main reasons are the low, priority given to mental health, the traditional centralization of mental health services in large, ineffective and often downright harmful psychiatric institutions, and poor application of cost-effective mental health strategies.

"There is also the stigma of mental illness, which inhibits sufferers from seeking treatment, and which may even limit the willingness of mental health care providers to intervene.

"Mental health depends on some measure of social justice, and mental illness, given its scale, must be treated effectively at primary level where possible."

Dr Brundtland has identified mental health as one of WHO’s main priority areas. The World Health Report, published annually by the Organization, will be devoted to mental health in its 2001 issue.