An uncorroborated rumor about the gunman, Adam Lanza, suggested that he suffered from Asperger’s syndrome—a now out-of-use term for a higher-functioning form of autism. By Saturday, a blog post by Lisa Long—“I Am Adam Lanza’s Mother: A Mom’s Perspective On The Mental Illness Conversation In America”—had gone viral, been retweeted hundreds of thousands of times, and republished on Gawker, Britain’s Daily Mail, and on the Huffington Post. Long, the mother of a 13-year-old with behavioral problems, argued, “It’s easy to talk about guns. But it’s time to talk about mental illness.”

There are various problems with Long’s impassioned piece when it comes to “talking” about mental illness, partly due to the fact it contained a slew of questionable diagnoses—Autism spectrum, ADHD, Oppositional Defiant, or Intermittent Explosive Disorder—which aren’t recognized as mental illnesses and better described as learning disabilities or disorders. Police Inspector Michael Brown, who runs the highly respected Mental HealthCop blog, called it “potentially the worst article I have ever read about mental health and violence following an atrocity.” Other critics took issue with the way Long had publically demonized her son as a potential mass murderer.  While some complained that Long herself was being demonized as a bad mother, the author from Boise, Idaho, issued a joint statement with one of her erstwhile critics about the need for accessible and affordable mental health care in the U.S.

The Huffington Post published a corrective article, “No Link Between Asperger’s Syndrome And Violence, Experts Say.” But to date, the corrective article has only received 2,500 Facebook “likes” compared to the more than a million received by Long’s original piece. The misinformation had circled the virtual world before the truth had even begun to get its cyber-boots on.

By Sunday, the line had grown into a swelling chorus. Erik Erickson, the founder and editor of the popular Republican website Redstate, was averring: “Discussions of gun control are easier to have than discussions about mental health.” The owner of one of the many gun ranges in the rural rolling hills around Newtown, Conn., was telling The New York Times: “A gun didn’t kill all those children, a disturbed man killed all those children.” David Rivkin, a constitutional lawyer who served in both the Reagan and Bush Sr. administrations, appeared on the BBC World Service to tell millions of listeners overseas: “It’s not about gun ownership, it is about mental illness.” “If there’s one unifying feature of all these atrocities,” Rivkin stated in an interview for the popular Newshour program on Monday night, “it’s that they were all committed by mentally unbalanced people who need to be confined for the protection of those around them and other people.”

The only problem with this argument is that it has no basis in fact. If mental illness was the key factor in multiple gun homicides like Newtown, then other countries would regularly experience the kind of carnage visited on towns and cities in the U.S. on almost on a monthly basis. But they don’t. In Britain, an advanced study by Manchester University into “Suicide and Homicide by People with Mental Illness” has found most people who kill more than one person are neither mentally ill, nor mental health patients, As Dr. David H. Barlow, a senior expert in comparative mental health-care systems and Emeritus Professor at Boston University, told The Daily Beast, “the incidence of mental illness is quite consistent across Europe and America.” Yet the statistics for the homicide and suicide rates are much higher in the U.S. than most of the rest of Europe, with Americans 100 times more likely to die to a gun-related death than in the U.K.

Despite the promise of a conversation about mental health, misinformation and ignorance became the norm in the aftermath of the Newtown tragedy.  British CNN host Piers Morgan suggested that anyone with a history of mental illness should be banned from owning a gun in the U.S., but that would include almost 50 per cent of Americans who are expected to suffer from some condition in their lifetime.  The Center for Disease Control and Prevention estimates that about 25 percent of U.S. adults currently suffer from some kind of mental ilnness—though this would include phobias and obsessive disorders. In 2011, government data calculated that around 5 percent of the U.S. population suffered from severe mental illness, while Professor Barlow estimates that somewhere around 1 percent  of the U.S. population will be suffering from psychosis—including delusions and hallucinations—at any one time. “But even they show an only slightly elevated risk of violence,” Barlow told The Daily Beast, “with a small increased risk of around 5 or 10 percent above normal.” Meanwhile, those who suffer from psychosis are much more likely to be the victims of homicide or kill themselves.

For Dr. Nadine Kaslow, professor and chief psychologist at Emory University School of Medicine—who was recently elected to the presidency of the American Psychological Association—the recent spate of generalized and pejorative statements made about mental illness are “extremely unfortunate” as they “stigmatize a whole group.”

“When I talk to my patients after an incident like Newtown,” Kaslow told The Daily Beast, “my patients differentiate themselves from these killers, because they say these people lack empathy.” Though Kaslow acknowledges that those with learning disabilities or mood disorders can be aggressive and display challenging behaviors, this doesn’t translate into calculated acts of violence. “We really do not see any correlation between Asperger’s syndrome and gun violence,” Kaslow reiterated.

Those millions of Americans who suffer from mental illnesses and learning disabilities have therefore become collateral damage in the soul-searching since the Newtown massacre. What conditions Lanza suffered from, or didn’t, will take a long investigation, but like other multiple-gun homicides, his atrocity required almost military-style planning and execution, which is unlikely given the cognitive and emotional deficits of acute psychiatric illness. It was this element of forethought and calculation which led to Anders Behring Breivik, the Norwegian right-wing extremist who killed eight with a bomb in Oslo then shot dead 69, mainly teenagers, holidaying on UtøyaIsland in 2011, being considered sane enough to face trial and a prison term in Norway. Though Breivik’s Islamophobic ideology could be described as crazy, the means Breivik chose to pursue his apocalyptic race war were rational and deliberative given those precepts, and he showed no sign of clinical psychosis.

In this light, Long’s imprecation to “start talking about mental illness rather than guns” looks like a distraction from the more probable factor to explain America’s elevated homicide and suicide rates: the U.S. is a complete outlier compared to other industrialized nations in its startling, almost 90 out of 100, number of guns per capita. Apart from the extreme youth and number of his victims, the other hallmark of Lanza’s massacre was the use of a semi-automatic Bushmaster AR-15 assault rifle (which has horrifically doubled in price since the Newtown attack). Assault weapons were banned until 2004, when the Federal Assault Weapons Ban was not renewed—largely thanks to the lobbying power of the National Rifle Association.

In what must count as one of the most successful campaigns in U.S. history, the NRA has managed to reduce support for gun control in the U.S. by 50 per cent in the last 20 years. One of its key lines of argument throughout that time has been that, “It’s not guns that kill people, but people who kill people.” On Friday the NRA’s Facebook page was taken down, and its Twitter feed went silent, and the organization seemed to have no response to the mounting calls for gun control in the wake of the most recent tragedy.

According to Mark Borkowski, a British PR titan with extensive knowledge of crisis-management campaigns, “anybody in this territory is equipped to deal with extreme events like this, and defend against or capitalize on them depending on what happens.” “The key thing is to sow doubt,” Borkowski told The Daily Beast. “Doubt is a product, and you have sleepers and advocates who are well briefed to construct a counter-narrative in times of crisis.”

There is no evidence that the NRA or any of its lobbying arms has been involved in any kind of crisis management in the last few days. However, opponents of gun control are now using a variant of the old NRA adage, “It’s not guns who kill people, but mentally disturbed people who killed people.” In doing so they are perpetuating what is effectively a slur against millions of Americans who suffer from mental illness, and stigmatizing a group who already suffer enough.