As classes start across the country and the promise of academic stress builds, more students are looking for something stronger than caffeine to keep them alert and focused. They are turning to stimulants intended to treat attention-deficit hyperactivity disorder, or ADHD.

Academic doping, as the trend is known, has surged in the past two years, and the abuse potential has spiked among students, according to Frank Granett, author of “Over Medicating Our Youth.”

A recent study from the National Institutes of Health found that more than a third of college undergraduates reported illicit use of stimulants intended to treat ADHD. Most found the drugs to reduce fatigue while increasing reading comprehension, interest, cognition and memory.

Although few students had information about the drugs, most could access them with ease, according to the report.

Illegal consumers of ADHD medication range from high school students cramming for exams to college students pulling all-nighters for a project. But students who don’t medically require these drugs could suffer from their long-term effects, experts say.

These narcotics, particularly Adderall, are potent and addictive, and over time can lead to anxiety, depression and even suicide, said Granett, who has 26 years of experience as an ADHD expert and pharmacist.

High achievers, big abusers

Usually high-achieving students are the ones who abuse the medication, said Dr. Emily Forrest, a developmental behavioral pediatrician at Florida Hospital.

If abused, these controlled substances can cause a decrease in appetite, leading to weight loss, said Forrest. A high dose can lead to irritability. When taken back-to-back, the medication can start to decrease a student’s concentration.

To prevent the medication from falling into the wrong hands, Forrest tells the parents of her patients to regulate the drug. She also advises college-bound patients not to tell friends they’re on the stimulants.

Taking ADHD stimulants to study applies to high school students as well, said Charlie DiGiorgio, owner of ProAcademic Solutions tutoring in Winter Park, Fla.

Since the SAT became more difficult in 2005, DiGiorgio said he’s seen more pressure on high school juniors and seniors to improve their test scores so they can get accepted into top universities and their intended majors.

“Some of them know they can’t do it, but they’ll do anything to get in,” he said.

Zombie students

DiGiorgio said younger students, particularly those in high school, often are curious and ask him about ADHD medication, its side effects and whether it will help their test scores.

“It’s not a miracle drug,” DiGiorgio said. “It’s something to be used as a crutch.”

Students taking such drugs before testing don’t necessarily improve their scores, DiGiorgio said, but he does see a short-term energy and confidence boost.

After a few days of cramming on the drug, DiGiorgio said, these stimulants begin to work in reverse — and his students look spent and delirious.

Then, he said, “they’re like walking zombies.”