Representational Image: President of Russia Vladimir PutinREUTERS/Sergei Karpukhin

Russian President Vladimir Putin was diagnosed with Asperger's Syndrome by none other than Pentagon back in 2008, as per a study conducted by its think tank that came to light on Wednesday.

The study by Pentagon's think tank, the Office of Net Assessment, said that Putin exhibited symptoms of the Asperger's syndrome, an autistic disorder, which affected "all his decisions" and made him want "extreme control" during a crisis.

The experts studied Putin's facial expressions and body language to theorise that his neurological development was 'significantly interrupted' during infancy, which gave him a sense of physical imbalance and a discomfort with social interaction.

"This profound behavioral challenge has been identified by leading neuroscientists as Asperger's Syndrome, an autistic disorder which affects all of his decisions," Brenda Connors, the author of the study and a senior fellow at the US Naval War College, wrote in the report.

"During crisis, to stabilize himself and his perceptions of any evolving context he reverts to imposing extreme control," she said.

However, even while the experts theorised that the Russian President had "a neurological abnormality," they said the theory cannot be proved as it required Putin's brain scan.

The 2008 study resurfaced after USA Today requested it under the Freedom of Information Act. It also accessed a 2011 study by the same think tank in which Putin was described as a "chess player" compared to then-president Dimitry Medvedev, who was referred to as an "action man."

Russia called the study "stupid", with Putin's spokesman Dmitry Peskov dismissing the claims.

"That is stupidity not worthy of comment," Peskov told Gazeta.ru news website on Thursday, according to AFP.

The Pentagon and the White House also played down the study, with the former claiming that the report did not reach the defense secretary or other top officials.

"The Office of Net Assessment did not send these reports to the secretary, and are not aware of any requests from any DoD (Department of Defense) leaders to review these reports," Lieutenant Colonel Valerie Henderson, a Pentagon spokesperson told AFP.

"I don't have any comment on that Pentagon report," White House Press Secretary Josh Earnest said.