WASHINGTON -- Attention-deficit hyperactivity disorder has variously been called "minimal brain dysfunction," "hyperkinesis" or a "defect in moral control."

Its hallmark symptoms are the inability to pay attention, get organized; start or finish tasks; a penchant for spacing out, forgetting or losing things; and, for some, the inability to sit still, stop talking or be patient and a tendency to act or blurt things out impulsively and long have been thought to affect only children. Particularly boys. Particularly disruptive boys in school.

In the 1990s, studies to determine the causes of ADHD began to find that it ran in families. And that, far from disappearing as children grew up, as had been the assumption, the disorder could last a lifetime.

Now, surveys by Harvard Medical School, the National Institute of Mental Health and the World Health Organization report that, conservatively, about 4.4 percent of adults in the United States, or 8 million people between ages 18 and 44, have ADHD, making it the second most common psychological problem in adults after depression. Though with only 15 percent having a diagnosis or seeking treatment, most of them apparently don't know it.

Adults with ADHD have been found to be more likely to lose a job, change a job or not show up for work, costing an estimated $77 billion a year in workplace failure. They are more likely to get divorced, go broke or be arrested.

They have four times as many accidents. They experience more relationship difficulties, sleep problems or substance-abuse addictions. They have higher rates of eating disorders, depression and anxiety than the general population, and lower educational attainment and earning potential.

Those with hyperactive symptoms also have been found to be at significantly greater risk for injury, nonsurgical hospitalizations and poisoning.

'A messy closet'

Nearly half of the estimated 5.2 million Americans in 2005 taking prescription ADHD medication -- the majority of which are classified as Schedule II controlled substances so powerful that they can be prescribed in only 30-day doses -- are adults.

Women, whose average age at diagnosis is 36 to 38, now account for the fastest-growing group taking prescription ADHD medication, increasing 164 percent between 2001 and 2009, according to Medco Health Solutions, which tracks prescription drug trends.

Much as the 1950s became the Age of Anxiety, with the rampant prescription of tranquilizers for stressed-out suburban housewives, have we entered a new Age of ADHD?

Absolutely, says Patricia Quinn, a physician in Chevy Chase, Md., who was one of the first to work with girls and women with ADHD 30 years ago. "Women with ADHD are the true 'Desperate Housewives,' " she says. "They come to me saying, 'I'm running as fast as I can to do what everybody else seems to do so effortlessly, and I can't keep up.' They stay in the closet a long time, suffering in silence. It's a messy closet. But they work hard to compensate, often staying up late into the night to get everything done. Until they get to the point where they're so overwhelmed, they're no longer able to cope."

It's not that women are suddenly coming down with ADHD. It has been there all along, Quinn says, and no one noticed.

As girls, these women were more likely to be spacey, inattentive, easily distracted and disorganized rather than hyperactive -- the last of which, for decades, was considered the key to diagnosis. For years, the disorder was diagnosed in 10 times as many boys as girls. Now it is diagnosed in adult men and women in equal numbers.

Quinn says that what traditionally has been expected of women -- keeping house, doing the laundry, grocery shopping, organizing children's activities, paying bills -- are exactly the mundane and organized tasks most difficult, if not impossible, for a wandering and impatient ADHD brain.

'Modern life'

Critics of the increasing ADHD diagnoses say the disorder is just the latest medical fad, that it is overdiagnosed and that too much medication is being prescribed too freely based on the results of studies paid for by large pharmaceutical companies looking to expand their market without understanding the long-term consequences to the human brain.

Joanna Moncrieff, a lecturer in the department of mental health sciences at University College London, has gone so far as to write in the prestigious British Medical Journal that ADHD does not exist at all in adults, calling the phenomenon the "medicalization of underperformance."

"There are lots of benefits to be had from getting the diagnosis, including sickness benefits, extra time to do exams, maybe laxer conditions or fewer duties at work, and a prescription of a recreational substance," she wrote. "I am convinced that the increase in women being labeled is because the drug companies are trying to tap the market for 'neurosis.' "

"If you're feeling very anxious and doing 100 different things at once, your attention is going to suffer, the ability to plan and be goal-directed is going to become increasingly difficult," says Daniel Goldin, a California psychotherapist who has written frequently about what he calls the "grotesque expansion" of the spacey, forgetful behaviors that psychologists have begun to label as ADHD. "All these women being diagnosed with ADHD are just overwhelmed and anxious. It's just modern life."

ADHD has been called | alternately a "disease of civilization" and the "American disease" for the high rates of diagnosis and prescription drug use here. (The United States alone accounts for well over 80 percent of the worldwide ADHD drug market.) One researcher has written that ADHD exists in any culture with compulsory education.

"Look," Quinn says, "Everyone loses their keys or glasses sometimes, shows up late once in a while or forgets to do the laundry. ADHD is on a spectrum of normal human behavior.

"To have the disorder, we're talking about people who do this all the time. To the point where it affects all aspects of their lives, their work, their marriages and their children. People don't realize how devastating ADHD is for women."