It's a growing problem at colleges and universities across the Garden State: students taking ADHD stimulant medication without a prescription, to help them stay awake so they can study longer.

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Some researchers estimate about 30 percent of college students are using these drugs improperly.

"They think of it pretty much like an energy drink, but in reality these are prescribed stimulants and can be dangerous," said Steve Liga, executive director of the Middlesex County chapter of the National Council on Alcoholism and Drug Dependence.

He said students are simply guessing when it comes to dosage.

"They could end up with a very high heart rate, they could end up with some serious insomnia, they could end up with jitters that actually keep them up way longer than they intended, and you're going to have people who even have a little bit of a hallucinogenic effect," Liga said.

According to Liga, these drugs can actually be classified as amphetamines.

"They are central nervous system stimulants, so by definition they're going to raise respiration and heart rate," he said.

Liga said someone with ADHD has a natural deficit of certain chemicals in the brain, and stimulant medication is used to supplement that and bring those deficiencies up to a normal level. If you don't have ADHD, however, you're boosting that level in the brain way higher than normal.

He also said most kids say they're taking these drugs to stay up and get better grades.

"But several very good studies show students who use Adderall regularly do not do any better, and in fact do worse than students who just get a good night's sleep," he said.

Liga said another potential problem is, once you get used to using Adderall, it's "going to become a habit for you, and before long your body is thrown completely out of whack and you're up when you're supposed to be asleep and then you need to take sleeping medication to try and get yourself back down."