FIGURES released by the American Psychiatric Association this summer revealed more Americans than ever before being successfully treated for mental illness. Between 16 and 12 per cent of the population annually receives some form of therapy for psychological problems compared to less than one per cent in 1950 - and that, percentage is certain to rise dramatically in the coming decade as neuroscience produces increasingly detailed maps of the brain's wiring, and as pharmacological companies multiply the selection of drugs targeting specific behaviour.
Mental illness - long regarded as medicine's stepchild - is now one of the profession's fastest growing areas. But some psychiatrists and analysts in the US are now criticising what they term over zealous diagnosis by clinicians and stressing the potentially disastrous social and economic consequences of the mental health industry's unprecedented expansion.
"Many sources of anxiety or discontent in the popular mind are classified as aliments, something that therapy or medicine can cure," says Robert J. Samuelson, Newsweek columnist and author of The Good Life and its Discontents, a sociological examination of the US.
"American society is obsessed with mood, dysfunction and self fulfilment. And when you regard the unavoidable consequences of living as disorders, mental illness becomes an infinitely elastic term - and an expensive one."
A proposal already approved by the US Senate and currently before the Congress gives weight to Mr Samuelson's prediction Under the new legislation, insurance companies will be required to provide a "parity of benefits" between physical and mental illness - at an enormous cost. The Congressional Budget Office estimates that the requirement will raise private insurance premiums by four per cent or $12,000 million in 1998. Employers are predicted to respond by culling wages by almost $11,000 million and by dropping insurance for more than 400,000 workers.
"I have a philosophical problem with government creating this kind of mandate," explains Samuelson. "The potential for lobbies of patients and providers besieging Congress to endorse a given treatment becomes enormous. And all pleas will be emotionally compelling." He also stresses the difficulty of drawing tight guidelines in such legislation.
"One reason for the disparity in coverage between mental and physical illness has always been the difficulty of defining who is mentally ill," he says. "That difficulty still exists. Diagnosing major depression, for instance, is still a grey area. A grey but profitable area, Samuelson adds. Worldwide sales of Prozac, the best known antidepressant, totalled $2,000 million in 1995.
Pharmological companies are predictably major backers of any legislation that is seen as destigmatising mental illness. But the American disability lobby has also been a powerful force in expanding the definition of disability to include mental impairment. The Americans with Disabilities Act of 1990 is commonly assumed to cover wheelchair access, learning aids and other provisions for the physically disabled, and to guard against discrimination in the workplace. During the ADA's first year, however, 10 per cent of all violation complaints concerned mental disabilities - second only to back problems. Mental impairment under the ADA is defined as "substantially limiting one or more major life activities ... any mental or psychological disorder such as mental retardation, organic brain syndrome, emotional or mental illness."
THAT last category is the problem, according to Gerald E. Zuriff, professor of psychology at Wheaton College, Massachusetts and a clinical psychologist at MIT. "No regulation specifies what constitutes an emotional or mental illness," Zuriff insists.
"Of course cases of mental retardation and schizophrenia are clear, but the act also covers oppositional defiant disorder, anxiety, mood and personality disorders.
The legally and professionally acknowledged source for the definition of such disorders is the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association and currently in its fourth edition. "Perusing the DSM is an eye opener," says Zuriff. "There are lists of personality traits such as arrogance, inflexibility, grandiosity, lack of empathy, shyness, hypersensitivity - combined in various ways and labelled `narcissistic personality disorder', or `avoidant personality disorder'." A sufferer of oppositional defiant disorder", for instance, would typically exhibit "negativistic, defiant, disobedient and hostile behaviour forward authority figures ... would often lose temper, deliberately annoy, people, be touchy, spiteful or vindictive.
Professor Zuriff also speculates on the repercussions in the workplace. "What will workers think of sensitivity training that encourages them to tolerate, and even empathise with, a co worker who is rude or lacks self control?" he asks. He is more concerned, however, with the social implications.
"When a personality trait becomes medicalised, that changes our mores, our interaction and who we are as a society," he insists. "And when what we used to regard as a character flaw is labelled a disorder, personality responsibility disappears. How can you be held responsible for an illness?"
Nobody who consults the current DSM could miss the message of personal responsibility, insists its text editor, Dr Michael First, a psychiatrist at the New York State Psychiatric Institute in Manhattan. "The preamble makes it very clear," says Dr First. "We say that just because your disorder is in the DSM that does not absolve you of personal responsibility." Pointing out that there are 300 different categories of mental illness, Dr First emphasises that new disorders are only included if they meet high standards - of strict scientific verification. "Of course personality traits in general are part off living," he concedes. "Nothing so vague could be included because the symptoms would have to constitute severe impairment. A new disorder is only listed if there is overwhelming scientific evidence of its validity.
Such evidence, particularly in the fast growing areas of anxiety, panic and obsessive competitive disorders in the US, increased dramatically in the last decade as the biological components of personality were explored. The resulting biology of temperament reveals specific genetic and biological factors that flavour personality and may play an important role in the development of personality disorder. More sophisticated tools probe brain chemicals and imaging techniques visualise how the brain itself works. Drugs acting on a particular short circuit proliferate on the market - serotonin for impulsivity, dopamine for eccentricity and suspiciousness, norepinephrine for sensitivity - the 21st century's update of Shakespeare's "Rosemary for remembrance".
But just because a certain type of behaviour responds to a drug, does that mean that it is a sickness? What about behaviour that is considered appropriate in one culture and aberrational in another? The percentage of children in the US being treated for attention deficit disorder, for instance, is far higher than the percentage in any European country, a fact that may say more about one culture's eagerness to suppress difficult behaviour chemically than it does about the severity of the symptoms.
