Why Methylphenidate Isn't a "Study Drug"

With less than two months left until the Suneung (CSAT), the Ministry of Food and Drug Safety (MFDS) released a statement with a clear, one-line message:

“There is no such thing as a ‘study drug’." Methylphenidate is strictly a treatment for ADHD. For those without the condition, it is prone to causing side effects like headaches and anxiety, and experiments have shown it actually degrades performance in problem-solving tasks.

What is Methylphenidate originally?

Methylphenidate is a central nervous system stimulant used to treat Attention Deficit Hyperactivity Disorder (ADHD).

According to a News Tomato article citing the Korea Pharmaceutical Information Center, it stimulates the central nervous system to regulate concentration and increase alertness. Immediate-release versions are used for ADHD and narcolepsy, while extended-release versions are used for ADHD. It is better known internationally by brand names like Ritalin and Concerta.

In South Korea, it is classified as a psychotropic substance—in other words, it is managed as a medical narcotic.

It is approved for individuals aged 6 and older, and the safety guidelines for ADHD medications issued by the MFDS in 2022 explicitly state that it should only be used for children and adults aged 6 and older who have been diagnosed with ADHD.

However, parliamentary data released on the same day shows that 964 children under the age of 6 were prescribed this medication over the last three years. It is a sign that a drug labeled as a “narcotic” is being treated as casually as a nutritional supplement.

Why does the rumor that it’s a “study drug” exist?

Even rumors have seeds of truth.

Psychostimulants can boost cognitive functions governed by the prefrontal cortex at low clinical doses, and a review by the Arnsten team at Yale University concluded that this effect is not limited to ADHD patients. Initially thought to be a “paradoxical reaction” specific to ADHD patients, later studies confirmed that individuals without the disorder also show responses during simple tasks.

Word of mouth skipped a few steps here. “Lab tasks improved slightly” morphed into “taking it raises your grades."

The scale of this rumor is visible in prescription numbers. Data received by Representative Seo Mi-hwa from the MFDS shows the following annual trends:

Changes in the number of people aged 18 and under prescribed methylphenidate

Year	Number of prescriptions (18 and under)
2023	119,205
2024	145,216
2025	169,274

It increased by 42% in two years. Focusing only on those aged 13–18, there was a 62.5% increase from 47,285 to 76,838, and for 17 and 18-year-olds facing university entrance exams, numbers jumped by 70.3% and 82.3%, respectively.

There is no evidence that this entire increase is due to abuse. ADHD diagnoses themselves may have increased.

Nonetheless, the pattern of the growth rate accelerating as students approach the Suneung age is hard to dismiss as a coincidence.

Healthy people who take methylphenidate show increased effort but decreased performance

So, what happens when a person without the condition takes it for complex tasks like studying or exams?

The experiment that most directly answers this question was published in Science Advances in 2023 by a research team at the University of Melbourne.

Forty healthy adults aged 18–35 visited a lab four times at intervals of at least one week. Each time, they took either methylphenidate, modafinil, dextroamphetamine, or a placebo. The pills were identical in appearance, so neither the participants nor the researchers knew what was being administered. The task was the “knapsack problem.” It involves choosing a combination of items—each with different weights and values—to achieve the highest total value within a weight limit. This simplifies the complex decision-making of daily life and closely resembles the structure of a student deciding which questions to solve first under a time limit.

The results matched the paper’s title.

For all three drugs, decision time was longer than with the placebo, and the number of attempts to find the answer increased.

Effort clearly increased. However, the value packed into the knapsack—the performance—was significantly lower than with the placebo.

The probability of finding the optimal solution (about 50%) did not change significantly, but the results relative to the effort exerted—or “the quality of effort,” as the researchers put it—declined.

More notably, who suffered the loss?

Participants who performed above average with the placebo dropped below average when taking the drugs, while those who were below average actually improved. The researchers attributed this to the drugs making problem-solving strategies more random.

Why “study drugs” pull down those who were already performing well

The key lies in dopamine and norepinephrine.

Methylphenidate prevents neurons from reabsorbing these two substances, increasing their concentration in the brain. The problem is that the prefrontal cortex follows an inverted-U curve regarding these substances. If levels are too low, function declines; if they are too high, it also declines. Being unable to think clearly when tired and having your mind go blank when extremely nervous are two ends of the same curve.

Animal experiments illustrate this shape perfectly.

In an experiment where rats were given methylphenidate, moderate doses improved performance in working memory tasks, but higher doses led to a decline in performance.

ADHD is related to dysregulation in the circuit connecting the prefrontal cortex and the striatum.

In terms of the curve, these individuals are on the left slope, and the medication pushes them toward the peak. Conversely, if someone already near the peak is pushed in the same direction, they fall over to the right slope. The result from the knapsack experiment, where high-performers saw the biggest drop, aligns with this model.

However, the knapsack study researchers specifically cited “increased randomness of strategy” as the cause, and the inverted-U curve is best viewed as a framework for understanding the background.

Personally, I found this part most interesting.

What the drug provides is the desire to keep at it longer, not better judgment. The researchers concluded that while smart drugs might increase motivation, the decline in the quality of effort—which is crucial for solving complex problems—offsets the benefits. The gap between the feeling of satisfaction from sitting at a desk for a long time and the actual score is created right here.

How far do methylphenidate side effects and legal penalties follow?

According to MFDS guidelines, if a healthy person takes the drug, they may experience headaches, anxiety, and in severe cases, hallucinations.

Buying drugs through social media without a prescription or receiving them from others can result in legal punishment under relevant laws.

Performance decreases, while physical and legal risks remain fully intact.

The scale of illegal distribution is not small either.

In line with the mock exam season, the MFDS conducted two special inspections in May and August 2026, uncovering 1,733 instances of illegal online sales or solicitation related to methylphenidate and requesting site blocks from the Korea Communications Standards Commission. Another special online inspection is scheduled for October, ahead of the Suneung.

Official YouTube and Instagram channels of the MFDS, the Ministry of Education, and the Ministry of Gender Equality and Family feature short-form videos regarding this abuse.

A diagnosis determines whether ADHD medication is necessary

Conversely, for a student who actually has ADHD, methylphenidate is a treatment that helps push them up from the left slope of the curve.

There is no reason to demonize the drug itself. The problem is using it for “test purposes” without a diagnosis. It is difficult to distinguish on your own whether the cause of your poor concentration is ADHD, sleep deprivation, or anxiety; making that distinction requires a specialist’s diagnosis.

We must all keep in mind that goals achieved through one’s own diligent capabilities, rather than reliance on medication, become the truly valuable results that make a life shine.