The incoming president of the powerful US National Rifle Association has linked deadly school shootings and other violence to the use of medications like Ritalin.
Oliver North, a retired Marine lieutenant colonel, has told Fox News Sunday that perpetrators of school violence "have been drugged in many cases" and "many of these young boys have been on Ritalin since they were in kindergarten".
North also blamed a "culture where violence is commonplace" pointing to TV and movies.
North's comments came after Friday's shooting at Santa Fe High School outside Houston, Texas left eight students and two teachers dead.
Investigators have given no indication that they believe the 17-year-old suspect, Dimitrios Pagourtzis, used Ritalin, which treats attention deficit hyperactivity disorder, or other drugs.
Pagourtzis' lawyer, Nicholas Poehl, says he's not aware that his client was on any specific medication.
He also said he was surprised that someone with North's experience with the criminal justice system would "make those kind of generalisations with a case that's less than 48 hours old."
An NRA spokesman, Andrew Arulanandam, confirmed North was speaking on the organisation's behalf and said "there are others who share this viewpoint."
George DuPaul, a psychologist at Lehigh University in Pennsylvania whose research has focused on ADHD treatment, said a deeper body of research exists on the effects of Ritalin and similar drugs than of treatments for any other condition in children. He said it doesn't support North's claim.
"There's really no evidence whatsoever that links treatment for ADHD with Ritalin and drugs like that with violence, let alone gun violence," he said.
If anything, DuPaul said, children tend to be less aggressive."
