For Devin Barclay, life with attention-deficit disorder has been a winding road. And seven years after he quit taking medication for the condition, "it's still winding," he says with a laugh.

But as the 23-year-old navigates his way into adulthood, he's managed to pay the roadside distractions a little less attention. And he's learned a thing or two about getting himself from one destination to the next without taking major detours.

In 1990, when Barclay was 7, he was diagnosed with ADD and began taking Ritalin — a stimulant medication that he and his parents referred to as "the thinking pill" — to help him sit still and pay attention in class. Over the next decade, almost 2 million American boys and girls were similarly diagnosed, an unprecedented growth of a medical condition that, before 1990, had been so rarely recognized that the national Centers for Disease Control and Prevention did not even track it.

Today, the children on the leading edge of a wave dubbed by some "the ADD generation" have reached the cusp of adulthood. And as they take on jobs or college, care for themselves away from home, enter into adult relationships and become parents, these newly minted grown-ups are carrying out a massive natural experiment.

It seems like only yesterday they were fidgeting in their seats, sprinting around their classrooms and daydreaming through addition and subtraction. Most, just like Barclay, struggled through elementary and middle school on Ritalin as the practice of medicating attention problems in children took off steeply in the United States: Between 1990 and 2005, production of the two stimulant compounds most used to treat ADD — methylphenidate and amphetamine — increased seventeenfold and thirtyfold, respectively.

Now many are choosing to do without the drugs that profoundly affected their experience of childhood and school and, in many cases, made it possible for them to learn alongside other kids in mainstream classrooms.

It is one of the first decisions of their adult lives. Mostly, it was parents who dictated whether and when they would start medications to sharpen their focus. But the decision to stay on or go off these drugs is one that these teens and young adults have made for themselves — with little research to guide them.

Whether the results will be momentous or slight is uncharted terrain, also, to researchers in the field of attention problems who are watching intently for answers — and hoping for better guidance for future generations of ADD sufferers.

MORE QUESTIONS REMAIN

U.S. society remains ambivalent about the diagnosis of ADD, a catch-all term used more commonly in the past that includes today's more well-known attention-deficit hyperactivity disorder. (Children diagnosed with ADD typically have difficulty focusing and paying attention. Those with ADHD are physically frenetic as well.)

Almost three decades after the psychiatrists detailed the condition, nagging questions remain: Does medicating a child with ADD help that child's wellbeing in the long term? Are there any negative consequences? And must it be a lifelong prescription?

Although most mental health professionals believe that about 2 in 3 children with ADD will continue to contend with the condition as adults, the truth is that "we have very few firm numbers," says Dr. Xavier Castellanos, a leading ADD researcher at New York University.

In short, "There are more questions that are unanswered than are answered," says Lisa L. Weyandt, a psychologist at Central Washington University who studies college-bound kids with ADD. Nobody, she says, knows how these fledglings will fare away from home and neighborhood schools, and whether the medications that appeared to help them in grade school will continue to be of use to them as adults. "They are," Weyandt says, "in uncharted territory."

One reason the terrain is unfamiliar is that this is the first generation of ADD kids for whom effective medication and accommodations for those with learning disabilities have made college a widespread possibility. "They're here and they're here in increasing numbers," Weyandt says. Barclay, now a freshman at Ohio State University, is typical of such youths in many respects.

When he was little, he says, his energy was so prodigious that his father had to sit at his bedside at night and hold his eyelids shut to help him fall asleep. "I was always going at 100 mph ... and I was making bad decisions on a regular basis," Barclay says. "I just didn't think of the consequences. I just charged ahead."

Looking back, he acknowledges that Ritalin did help academically. But he also felt that it blunted his natural sociability, made it "hard to feel passionate about anything." And the same intensity of focus that helped him in class, he believes, impaired his instincts on the soccer field — a troublesome side effect for a rising soccer star.

He quit Ritalin as a freshman in high school. Off the drug, he says: "I felt more like a happier person. I just felt more like myself," voicing an observation heard again and again among young adults who abandoned their ADD medication.

Restlessness of mind remains, but the ADD has changed, and so has he. Adult life has a wider range of choices than grade school offered. He hopes that if he makes the right ones, he can make it all work.

Barclay has plenty of company, according to Mariellen Fischer, a professor of neurology at the Medical College of Wisconsin. Among the 150 children she has tracked well into their 20s, "discontinuation of the medication (has been) by far the vast norm," she said. Of those diagnosed and medicated for ADD as children, she estimates, about 9 in 10 are off those medications by the time they reach 21.

By high school, she adds, the most glaring of ADD symptoms — the inability to sit still — has typically eased. And, just like their peers without ADD, these young patients are driven to question the judgment of the people in charge of their lives.

Those challenges are focused on the parents, teachers, physicians and therapists who labeled them different and put them on medication that is a daily reminder of that judgment.

For parents, this moment of awakening can be a frightening challenge. But experts warn that it's better to brace for change and have a plan than to dig in or — worse — be taken by surprise.

"You can tell a 7- or 8- or 9-year-old to take his medication and he will. By 12 it starts to get tricky, by 14 it's difficult, and by 16, it's impossible," Castellanos says. "You get into issues of autonomy and (charges such as) 'You're just trying to drug me.' "

ADD: WORK IN PROGRESS

What few studies there are suggest that ADD often causes problems after kids grow up. For 13 years, Fischer and her colleague Dr. Russell A. Barkley tracked 147 children diagnosed with ADD by age 7. They compared them with kids from the same neighborhoods without ADD.

In 2005, they reported that young adults with a childhood ADD diagnosis were more likely to have dropped out of high school and to have been fired from jobs. They were more likely to have had sex earlier and became parents at a younger age than their non-ADD peers. They had higher credit card debt and fewer savings, and were far less likely to attend college.

Young adults with ADD also appear to have more motor vehicle collisions and traffic citations and are more likely to experiment with illegal drugs. But the data suggest that ADD sufferers who took prescribed medication were less likely than those who did not to use illegal drugs.

Beyond that, the story is fuzzy because children that Fischer and Barkley tracked did not sort themselves into neat research categories. Some of the children diagnosed with ADD did not take medication. Others took medication steadily. Most took them for a while and then, at various ages, quit.

And that leaves researchers in the dark. They don't know whether taking medication for some stretch of time, or during some critical period, will offer protection against these later, adult ills — even if, as adults, people decide not to medicate themselves any longer.

In that sense, Devin Barclay's peers are writing the textbook on ADD as they go along.

IMPULSE CONTROL

"We are the first generation of Ritalin kids," says 31-year-old David Cole who, as an undergraduate with ADD at Brown University, co-wrote "Learning Outside the Lines," a book about navigating college with a learning disability. (He's now an up-and-coming artist based in Rhode Island.) Certainly, such medication has made success in life a possibility for kids like himself, he adds — but once school is out, "it's whatever works for you," he shrugs.

At 23, Devin Barclay has begun to learn how to harness his attention to tasks he needs to accomplish. He wouldn't dream of bringing his laptop to a busy coffee shop to do homework, or to have the television on while reading. He plans his school work in short spurts of no more than an hour, and is careful to sequence his obligations — term papers, bill paying, soccer coaching duties — so they don't scramble his attention.

"I get things accomplished. It's probably not as efficiently or as quickly as other people, but it happens in my own way," he says.