A 2008 Pentagon think tank study claimed that Putin has Asperger's syndrome
Putin's "neurological development was significantly interrupted in infancy," wrote Brenda Connors, an expert in movement pattern analysis at the US Naval War College in Newport, RI.
She added that movements reveal "the Russian President carries a neurological abnormality."
The researchers said they can't prove their theory for certain because they haven't yet been able to perform a brain scan on the Russian president.
Connors and her colleagues work in the Office of Net Assessment - a secretive, internal Pentagon think tank that helps devise long-term military strategy. Her team has reportedly done several studies on Putin over the years.
Asperger's - long used to label "mild" cases of autism where cognitive development is normal despite social difficulties - is no longer an official diagnosis; since the report came out, it's been folded into the broad category called "autism spectrum disorders."
In any case, what was formally known as Asperger's is challenging to diagnose, likely even more so from afar. There is no brain scan or blood test. Instead, a professional looks for a complicated constellation of symptoms like "persistent deficits in social communication and social interaction" and "restricted, repetitive patterns of behavior, interests, or activities."
The report cites Dr. Stephen Porges, a University of North Carolina psychiatry professor, who concludes that "Putin carries a form of autism," although he told USA TODAY that he wouldn't say that Putin has Asperger's. He also noted that Putin appears to be "defensive in large social settings."
The 2008 report and a 2011 study were provided to USA TODAY as part of a Freedom of Information Act request. This report did not reach former Defense Secretary Chuck Hagel or his predecessors, according to Lt. Col. Valerie Henderson, a Pentagon spokeswoman.
Check out the whole report here.