Russian President Vladimir Putin attends a meeting with his Macedonian counterpart Branko Crvenkovski on the sidelines of the Energy Summit of Southeast European Countries in Zagreb June 24, 2007. Reuters/Damir Sagolj Vladimir Putin's spokesman "angrily dismissed" a Pentagon think tank's claim that the Russian president has Asperger's syndrome.

"That is stupidity not worthy of comment," spokesman Dmitry Peskov said, according to AFP.

His comment comes after USA Today reported a 2008 study from a Pentagon think tank, which claimed that Putin has Asperger's syndrome, "an autistic disorder which affects all of his decisions."

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, Rhode Island.

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."

What was formally known as Asperger's is challenging to diagnose — 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 2008 report and a 2011 study were provided to USA TODAY as part of a Freedom of Information Act request. Pentagon played down the study, saying it apparently never made its way to the desk of the defense secretary or other top decision makers, AFP notes.