Though Zardari's spokespersons contend that he had been cured, the American officials were wary of Zardari having a partial control over Pakistan's nuclear arsenal if elected to the post in the September six presidential polls, Newsweek reported.

"Typically (the US) would not want that kind of person involved in a nuclear chain of command," said Pete Hoekstra, ranking Republican on the US House Intelligence Committee.

Doctors hired by Zardari had reportedly diagnosed him with problems like including dementia, depression and post traumatic stress disorder.

Lawyers for Zardari, the report noted, argued in London's high court that he was too ill to testify in corruption-related cases, and they submitted recent mental health evaluations as evidence.

In March 2007, the Financial Times reported, New York psychologist Stephen Reich concluded Zardari was "chronically anxious and apprehensive" and had thoughts of suicide, though he had not acted on them.

The newspaper wrote that a New York psychiatrist, Philip Saltiel, found that Zardari's long imprisonment in Pakistan while facing corruption probes had left him with "emotional instability" as well as memory and concentration problems.