> “Mr. Assange has been deliberately exposed, for a period of several years, to progressively severe forms of cruel, inhuman or degrading treatment or punishment, the cumulative effects of which can only be described as psychological torture.“
That quote lacked information on who was exposing him and what that exposure actually was, so I followed your source. That source elaborates as follows:
> “In the course of the past nine years, Mr. Assange has been exposed to persistent, progressively severe abuse ranging from systematic judicial persecution and arbitrary confinement in the Ecuadorian embassy, to his oppressive isolation, harassment and surveillance inside the embassy, and from deliberate collective ridicule, insults and humiliation, to open instigation of violence and even repeated calls for his assassination.”
Apart from the last item, that all sounds either like hyberbole ("systematic judicial persecution" -- unless he is above the justice system, that's the system at work), or self-inflicted.