Asperger's not an explanation for Lanza's Connecticut killing spree, experts say By many accounts, Adam Lanza didn't fit in. Family friends and neighbors describe a young man who went far beyond shy in avoiding people, who had few or no friends, and who dressed unlike most of peers, buttoning up his shirt to the top and carrying a briefcase to high school instead of a backpack. Several people, including Ellen Adriani, a friend of his mother, Nancy Lanza, have now said he had Asperger's, a type of autism, although there's been no official medical confirmation of this. "Nancy was always concerned about Adam because of his Asperger's and the typical behavior that goes along with that," Adriani told NBC News. If Adam Lanza did have Asperger's syndrome or another form of autism, he committed the unfathomable murders of 20 children, six school staff and his own mother despite the condition, not because of it, experts agree. The kind of carefully planned, violent attack like the killings in Newtown, Conn., on Friday would be out of character for someone with Asperger's, said autism expert Travis Thompson, Ph.D., of the Special Education Program at the University of Minnesota. I have known a lot of people with Asperger's and I have never known one who is violent. They are very anxious," Thompson said. They have a lot of problems with anxiety and they have problems with relationships with other people too but that doesn't translate into violence. When they are little kids, they have tantrums because they don't know what to do and they feel adults don't understand them. When they become older they develop mechanisms and since they are usually very verbal they can ask questions. Parents of kids with Asperger's worry about the discrimination that could come from all the speculation. "I think a lot of parents who are dealing with this already are awash with anxiety and uncertainty, and when someone sits in front of the camera and says people like my son are dangerous because of an association with a condition, it's scary," says Ron Fournier, editorial director at National Journal, who has written several recent high-profile commentaries about his son with Asperger's. Julie Steck, a child and pediatric psychologist in private practice in Indianapolis, said people with a developmental disorder like autism are more likely to have a range of other physical and mental disorders. That's in part because of the genetics, in part because of the stress of coping with the disorder itself, she said. Family friend Adriani said Adam Lanza also had an unusual condition where he didn't feel physical pain. If he were to cut himself or even if he fell down or if he injured himself he wouldn't necessarily know how severe it was because usually the pain is, oh something's wrong. So if he cut himself he wouldn't even necessarily know it," she said. Richard Novia, who was Lanza's tech club adviser at Newtown High School, backed that detail in an interview with the Associated Press. "If that boy would've burned himself, he would not have known it or felt it physically," Novia said. It's not clear to experts if that is tied to Asperger's. "Individuals with Asperger's often have poorly modulated responses to pain - they may over-react to something which seems minor to others but totally block out or not respond to something we would see as painful," says Steck. However, I am not familiar with there being a correlation with not feeling or being able to respond to pain at all. Russell Hanoman, another friend of Nancy Lanza, described Adam as being obviously uncomfortable around other people. "I remember when I first met him, he deliberately stood maybe six feet away from me and took three exaggerated steps toward me, stuck out his hand, shook it, put it back, and three exaggerated steps back," Hanoman told NBC News. Thompson also said it is unlikely a person with Asperger's would have plotted something like Friday's shootings over a long period of time without telling someone about it. "I am not saying a person with Asperger's would not do something like this," he said. It is possible a person with Asperger's could have done something like this but so might someone who was depressed or someone with schizophrenia. Or someone with no diagnosed mental illness at all. Descriptions of Lanza's painfully awkward ways have fueled speculation that he might have been lashing out after a childhood of having been bullied. But there's no evidence that Lanza was bullied, and Thompson doesn't see the connection between any possible bullying and the murders. Why would he go in and kill a bunch of little children? Thompson asked. One thing psychologists do agree on - mental health is still not adequately diagnosed or treated in the United States, and especially not among young people."We need to destigmatize it so that people seek treatment for their children and for themselves. I think obviously that funding is a huge issue," said Steck, the Indianapolis child and pediatric psychologist. It is very under recognized and under financed and many of the programs out there are not delivered in a very effective manner. Connecticut Gov. Dan Malloy agrees. "Mental illness has long been relegated to a different discussion, as has physical health," Malloy said at a Hartford, Conn., news conference Monday about the shootings. It is not a distinction that I think serves our country. We need to begin in earnest the process of removing that distinction. NBC News" Michael Isikoff contributed to this report.