(CNN) Oliver North, the National Rifle Association's incoming president, has suggested that a certain medication to treat attention deficit hyperactivity disorder, or ADHD, could be partially responsible for the recent gun violence in American schools: Ritalin.

"The problem that we've got is, we're trying like the dickens to treat the symptom without treating the disease, and the disease in this case isn't the Second Amendment; the disease is youngsters who are steeped in a culture of violence," North said Sunday in an interview with Fox News Sunday.

"They've been drugged in many cases. Nearly all of these perpetrators are male, and they're young teenagers in most cases, and they've come through a culture where violence is commonplace," he said. "Many of these young boys have been on Ritalin since they were in kindergarten. Now, I am certainly not a doctor, I'm a Marine, but I can see those kinds of things happening."

The comments from North came on the heels of a shooting last week at Santa Fe High School in Texas, where eight students and two teachers were killed. A suspect, 17-year-old Dimitrios Pagourtzis, was taken into custody. This year alone in the United States, there have been 22 school shootings in which someone was hurt or killed, which averages to more than one shooting a week.

Among those was the massacre at Marjory Stoneman Douglas High School in Parkland, Florida, this year. The shooter, 19-year-old Nikolas Cruz, had a history of ADHD. His psychiatric records obtained by CNN showed that in 2016, he was on two types of medication that are routinely prescribed for ADHD, but neither was Ritalin.

As for the shooting at Santa Fe High School, Nick Poehl, one of Pagourtizis' lawyers, said Monday that, as far as he knew, his client was never prescribed Ritalin and had not been diagnosed with ADHD before the incident.

Ritalin, or methylphenidate, is in a class of medications called central nervous system stimulants, which are often used in children and adults to help control symptoms of ADHD or to treat narcolepsy.

Many mental health experts caution against suggesting a connection between medications such as Ritalin and increased aggression or violent behavior in schools.

"No, there is no evidence of that. In fact, if anything, there's stronger evidence that Ritalin and other medications that are used to treat ADHD would reduce violence and aggressive behavior," said George DuPaul, a professor in the school psychology program at Lehigh University College of Education in Bethlehem, Pennsylvania.

Long-acting methylphenidate was found to be effective in the treatment of defiant and aggressive behavior among 85 children and adolescents in a five-week randomized clinical trial, the results of which were published in the Journal of Child and Adolescent Psychopharmacology in 2007.

"The drugs also tend to help with reducing impulsive behavior and reducing hyperactivity, or high activity levels, and those are the primary symptoms of ADHD," DuPaul said, adding that the drugs help with increasing attention to tasks and school assignments.

"We've been studying drugs like Ritalin for over 50 years, and there are hundreds and hundreds of research studies on the impact of these medications on individuals with ADHD, and although there are side effects for sure," he said, "there is no evidence that long-term use of these medications leads to violence or aggressive behavior."

Serious side effects of Ritalin include heart or mental problems, slowing of growth in children, seizures (mainly in patients with a history of them), eyesight changes or painful and prolonged erections, according to the drug's medication guide.

Common side effects include headache, stomachache, trouble sleeping, nausea, decreased appetite and nervousness, according to the guide.

American Psychological Association President Jessica Henderson Daniel released a statement Friday in response to the school shooting in Santa Fe, Texas.

"As our nation confronts yet another horrific school shooting, it is imperative that we not become inured to these tragedies. We must act as a society to make our schools safe and ensure that students and teachers do not live in fear that they could be next," Daniel said.

"The American Psychological Association calls for evidence-based solutions to stop the gun violence that has become a public health crisis and is tearing our country apart," she said. "These include restricting access to guns for people who are at risk for violence and working with psychologists and other experts to support best practices for keeping our children safe in school."