updated 12:32 PM EST, Wed November 27, 2013  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Worst mass shootings in U.S.  Editor's note: Christopher J. Ferguson is chair of the psychology department at Stetson University. He is the author of the novel "Suicide Kings."  (CNN) -- A new report said that "Super Mario Brothers" was a favorite video game of Sandy Hook shooter Adam Lanza. He had no history of violent behavior. But he was interested in mass murderers.  Nearly a year since the tragic shooting at Sandy Hook Elementary School where Lanza killed 26 people, Connecticut's state attorney office released its official report that tried to piece together what happened. The investigation provided some insights into the life and actions of the gunman, but his motive remains a mystery.  The report suggests that improving the delivery of mental health care to those with chronic mental illness may be an important element in reducing certain acts of violence, and that mass shooters are not "enthralled" with violent video games.  Lanza was a young man with clear mental health issues. He appears to have been isolated, even communicating with his mother mainly through e-mail despite their living in the same house. It seems he had some obsessive-compulsive qualities related to food preferences, dislike of loud noises or being touched, and a disdain for holidays and birthdays.  Lanza's issues with social communication and problems with crowds worsened in later years. He was also diagnosed with Asperger's syndrome. The report notes he declined to take any medications or participate in behavioral therapy. However, it makes no mention of him being aggressive or violent before the shooting.  The report does suggest he had an interest in things related to death and mass shootings. Lanza had a spreadsheet of mass murderers. He also had literature related to pedophilia -- but no child pornography.  From all of this information it's hard to draw any conclusion. But it's fair to say that chronic mental health issues are common among mass shooters, including Lanza.  On the other hand, it's important to note that most individuals with chronic mental illness are not violent. Nor is Asperger's syndrome linked to violence.  The tragedy at Sandy Hook may represent a missed opportunity to have a frank discussion about our inadequate mental health system. Other than a few nods to the issue we didn't have that discussion. Mainly, we talked about gun control and video games. This is too bad.  While it's certainly true that most mentally ill people are nonviolent, research also suggests that chronic mental health issues such as psychosis or depression are risk factors for violence, particularly when mixed with chronic anger.  Follow us on Twitter @CNNOpinion  We must do more to take away the stigma associated with mental illness. Yet pretending no relationship exists between mental health issues and some acts of violence may backfire by reducing our sense of urgency in improving the mental health care system.  As for the issue of video games, the Sandy Hook shooting set off a year's worth of speculation about the harm violent video games may or may not do and whether they are a threat to society. The report, in the end, had relatively little to say about video games and did not link them to the shooting. For example, much like any 20-year-old, Lanza played an assortment of both violent and nonviolent games. But it turns out that he was fond of games that were nonviolent, particularly "Super Mario Brothers" and "Dance Dance Revolution."  Despite speculation and efforts by some politicians such as Sen. Jay Rockefeller and Rep. Frank Wolf to tie mass shootings to violent video games, Lanza's video game playing was unremarkable.  Once again we are reminded of our society's eagerness to assign blame quickly even if evidence suggests otherwise. For example, the youth violence rate has actually declined by nearly 90% during the video game era. That statistic is one reason why policymakers should not rush forward with regulations before we get the full picture.  In the end, we may simply never know why Lanza did what he did other than that he was a disturbed, angry young man who made the choice to do something horrible. Perhaps it is time to stop looking for external explanations for his behavior and acknowledge that this catastrophic choice was his and his alone.  As we approach the one-year anniversary of the shooting, our thoughts and prayers will be going out to the families of the victims of Sandy Hook.  The opinions expressed in this commentary are solely those of Christopher J. Ferguson.
Chris Ferguson says the official report about the Sandy Hook shooting offers insights but no answer to the killings.