KANSAS CITY, Mo. - A University of Kansas freshman took a break from shooting hoops with friends outside his dormitory to talk about what some students call "study pills."

As final exams approached last semester, he took a couple doses of a prescribed stimulant called Adderall. "But all they did was make me feel nervous," said the chemical engineering major. "I'm off of it now."

He still has a vial of leftover pills he used for his attention issues in high school. And that's why he asked that his name not appear in this article: He didn't want to be pressed by dormmates to supply them with an illegal focus boost for upcoming finals.

The controlled stimulants that many college students seek, if only for a momentary edge, carry familiar brand names such as Adderall, Vyvanse, Focalin and Ritalin. They're all standard drugs for treating attention deficit hyperactivity disorder, often successfully.

Their misuse, however, is thought to be on the rise at campuses nationwide - creating a potentially serious health hazard and trips to the emergency room for students not diagnosed for ADHD.

The extent of the problem is anyone's guess. Because of what experts consider a lack of reliable research, illicit dealing of ADHD drugs either is infrequent on campus or something so commonplace as to be the college crowd's best-kept secret.

"The only people who don't know about it are the parents," said University of Kentucky communications professor Alan D. DeSantis. "I'm sure the majority of my students will be using Adderall at some time during finals week. It's really built into the climate and culture of today's college life."

DeSantis has analyzed several years' worth of surveys of Kentucky undergraduates to conclude that at least one-third of the student body has taken ADHD medication without prescriptions. Another 8 percent use the drugs legally under a doctor's supervision, he said, and half of them provide pills to other students.

The incidence of use appears to be higher among Kentucky seniors and juniors than for younger students, DeSantis added.

Tweets tracked

Assessing a variety of surveys, a 2008 study published in the Journal of American Child Adolescent Psychiatry offered a not-so-precise range of 5 percent to 35 percent of college-age people taking attention-deficit stimulants not prescribed for them.

A University of Missouri survey found a usage rate in between. About 12 percent in a sample of Mizzou students admitted to using controlled stimulants or painkillers, prescribed or illegally, said Kim Dude, director of the University of Missouri's Wellness Resource Center. "Eighty-five percent of the students don't use any of that."

But she does agree with the KU freshman - don't let on if you've got attention-deficit pills.

"We urge students and their parents from the start: Don't tell anybody," Dude said. "They'll run into peer pressure to sell it or give it away" to other students.

This month, data-miners at Brigham Young University issued a study that tracked Twitter references to study pills. Searching keywords such as "Adderall," "college" and "cramming" over a six-month period, lead researcher Carl Hanson allowed, "We don't have all the answers" on the frequency of legal use or abuse. But the study did conclude that tweets about the drug were heaviest among students in the Northeast and South, and lightest among students in the Plains and Southwestern states (including California).

Also, the report summary stated, "tweets about Adderall peak sharply during final exam periods."

Said Hanson: "I'm concerned about the social norming thing. If students perceive (taking stimulant medication) as normal because it's talked about and tweeted a lot, they'll take the risk."

Dangerous practice

Millions of Americans have taken prescribed ADHD medication - often intermittently - without experiencing negative side effects. But an under-30 generation raised on the practice might not be aware of the dangers of taking even modest dosages without a thorough diagnosis, said psychiatrist Tahir Rahman of the KU School of Medicine.

"If you're depressive or have bipolar disorder, taking a drug such as Adderall could be throwing gasoline on a fire," Rahman said.

Nationwide, the number of emergency room visits related to abuse of ADHD drugs rose to 31,224 in 2010 - more than double the number recorded five years earlier, according to a federal report released in January.

Such ER visits by people ages 18 to 25 nearly quadrupled in that time, the Substance Abuse & Mental Health Association reported. It is not known how many of those patients were college students.

Colleges around the country are tightening their procedures to limit student access to stimulant medicine.

"Some campuses have outright stopped prescribing stimulants," said Stacy Andes of the American College Health Association. Others, including KU, require students to present copies of at least two diagnostic tests given by doctors or mental-health professionals.

The drugs easily can be obtained off campus in most college towns, said DeSantis of the University of Kentucky. A clinic or family practitioner may ask patients to fill out a questionnaire that asks if they have trouble focusing or completing assignments.

"For the most part, students (seeking medication) know how to answer those questions," DeSantis said.

Downing Adderall to perform better on tests raises questions beyond medical ones: Is it the educational equivalent of using steroids to cheat in sports? Are students who choose not to use stimulants, or those who can't afford them, chasing degrees at an unfair disadvantage?

Psychiatrists debate whether the drugs do much at all to help people not diagnosed with ADHD, other than to keep them awake so they can cram for tests.

Girding for finals in a library study room at U of Missouri-Kansas City, Govinda Koirala wrinkled his nose when asked if he would ever consider a pharmaceutical boost. "I drink coffee," said the junior studying mechanical engineering. "And the latest I stay up studying is 11:30" p.m.

His secret to academic success? "Just relax. Sleep well. Do what's good for your mind."

Must work. Koirala has a 3.91 grade-point average.