He'll have trouble proving that - given he'd showed no prior evidence of it.My money is on him suddenly developing Aspergers and having the lefty human rights lawyers weaponising it to stop his extradition
My money is him claiming some sort of mental condition derived from long confinement at the Ecuadorian embassy. Given he damaged UK national security as well as that of the US, I suspect any attempt to claim a medical condition should prevent extradition will be given short shift. I would also expect the US government to flag they have the medical facilities to treat the claimed condition.
Assange is finding out actions have consequences. Had be been discerning in his leaking of the diplomatic cables, and redacted some of the sensitive information, he would have been able to claim he was carrying out legitimate journalism. Dumping hundreds of thousands of diplomatic cables into the public domain without first vetting the contents seems a clear attempt to harm US and UK interests.
He's going to end up in a US prison for the rest of his life, and I for one think it well merited.