Incoming NRA President Oliver North has a strange theory about why Dimitrios Pagourtzis, 17, marched into Santa Fe High School outside of Houston, Texas, last Friday and killed 10 people with a shotgun and .38 revolver, while wounding 13 others. North, the disgraced former National Security Council staffer who funneled proceeds from arms sales to Iran to benefit Nicaraguan terrorists during Ronald Reagan’s presidency, blames violent video games and Ritalin.

“The problem we’ve got is we’re trying like the dickens to treat the symptom without treating the disease,” North said on Fox News Sunday. “And the disease, in this case, isn’t the Second Amendment. The disease is youngsters who are steeped in a culture of violence, they’ve been drugged in many cases. Nearly all of these perpetrators are male and they’re young teenagers in most cases.

“Many of these young boys have been on Ritalin since they were in kindergarten,” North claimed, without evidence. “Now I’m certainly not a doctor, I’m a Marine, but I can see those kinds of things happening and endangering those two gals.”

North is perpetuating his argument in response to the Santa Fe High School shooting, but there is no evidence so far to indicate Pagourtzis was diagnosed with ADHD, or that he was prescribed Ritalin in response to such a diagnosis. His argument, therefore, can’t even apply to the most recent high-profile shooting, making it unclear exactly how and what prompted North to allege any such link.

But beyond that, North also lacks any real evidence that suggests Ritalin, or any other psychiatric drug, is to blame for any of the shootings we’ve seen in recent years. That’s because the evidence doesn’t exist.

“I’m not aware of any case of school shooter where there’s a link in psychiatric medication and school shooting,” said Peter Langman, a psychologist and expert in school shootings and the director of SchoolShooters.info. Langman has previously investigated the link between psychiatric medications and school shootings, and has, effectively found that the claims that drugs are fueling violence across the country—claims often pedaled by InfoWars and similar havens of fear mongering nonsense—are bunk.

Before we get into why, it’s probably worth explaining where the argument comes from. Ritalin is one of the trade names for methylphenidate, a drug that is used to treat attention deficit hyperactivity disorder, or ADHD. It’s a stimulant, and works by increasing activity in the central nervous system (via dopamine) in order to increase alertness and focus in individuals who have trouble paying attention and controlling impulsive actions.

While the drug is well-tolerated by most people, there are—as with most other psychiatric drugs—a slew of possible side effects that could manifest as a result, including increased anxiety, depression, and even severe mood swings that are indicative of psychosis or hyper-aggressive behavior. Still, many of those symptoms are associated only with high doses and drug abuse that veers into overdose territory. And in fact, Ritalin has demonstrated an ability to actually curb aggressive behavior in children with ADHD.

In his own work, Langman examined the entire medication-to-shooting link from two approaches. The first is individual—whether or not the school shooters themselves used psychiatric medication before and during the these events, even if those drugs were taken as part of a prescription or being abused. Some sites claim nearly every school shooter was involved with drugs of some kind—a claim Langman found false. In a survey completed in September 2015, he found that only 15 percent of all school shooters—whether they were teenagers or adults—were using psychiatric medications at the time of their attacks or had used such medications a month prior (PDF).

Furthermore, in cases where Ritalin was involved, such as Kip Kinkel’s 1998 murder of four people at a high school in Oregon, or Eric Hainstock’s 2006 murder of his principal at high school in Wisconsin, Langman found that the medication actually did was it was supposed to do: improve behavior and mood. In fact, both individuals had been off the medication at least several months before they committed their shootings. There’s absolutely no reason to believe Ritalin caused those attacks.

The second way to examine the argument made by North and others is from a societal perspective. Ritalin use has absolutely increased over the last few decades. But you know what else has decreased during that time? Violent crime in the U.S.

“We actually saw a decrease in violence as medication use increased” in both males and females, says Langman. That doesn’t mean correlation equals causation, and more medications are resulting in less violence. But it definitely means you can’t competently link Ritalin, or any other psychiatric drug, to the school shootings we’ve seen as of late.

Trying to tie Ritalin to school shootings isn’t just faulty logic—it’s terribly irresponsible. “It’s a very widely used medication,” says Langman. A great number of people have benefitted from Ritalin and rely on it as a way to help them control their symptoms throughout the day. Trying to turn it into cause du jour doesn’t just take attention away from actual factors that contribute to mass shootings, but it also threatens the livelihoods of the millions of people who use such medications to live stable lives.