By Kathryn Westcott
BBC News website
Reports this week that the CIA has concluded that Cuba's President Fidel Castro has the debilitating Parkinson's disease shed light on the agency's practice of medical and psychological profiling.
CIA experts apparently made President Castro's latest "diagnosis" after analysing his public appearances.
The CIA apparently studied TV footage of Castro
For decades, the CIA has employed analysts to provide psychological and medical assessments of foreign leaders - both friend and foe - for the president and other top US officials.
Often, the CIA leaks aspects of such assessments to the media.
Ronald Kessler, author of The CIA at War and Inside the CIA, says that "profiling can come under the category of covert operations.
"This covers a broad category including propaganda and disinformation. It would usually be directed at the foreign press," he says.
"Given this, it is conceivable the latest assessment of Castro's health is being used in this way."
President Castro is no stranger to CIA "covert operations". In the past, such operations included attempts to assassinate him.
Operation Mongoose sought to eliminate him with a number of unlikely weapons. In 1963, agents hatched a plot to kill the cigar-smoking communist with an explosives-packed cheroot.
Rumours about the 79-year-old Cuban leader's health have circulated for years. Recently he joked that when he really died, no one would believe it.
The rumours have grown more frequent as Fidel Castro grows older and interest in his succession intensifies.
The question of the succession may not be that pressing, however. The Cuban president has denied the reports of Parkinson's and one CIA profile of him reportedly notes a history of longevity in the Castro family, with his mother living until the age of 92 and his father to 84.
Bin Laden tapes would have been scoured for clues about his health
US officials have long seen profiling - both medical and psychological - as a valuable tool to establish negotiating tactics, get an edge in a crisis or just establish how a leader may act in a particular situation.
Famously, in early 2003, US government officials called on the services of former top CIA psychiatrist Jerrold Post - who had spent years psychoanalysing Saddam Hussein from afar - to guide them in their decisions as they engaged Iraq in a high-rolling game of cat and mouse.
It was Dr Post who established the agency's Centre for the Analysis of Personality and Political Behaviour in the early 1970s.
During that time, Dr Post, who now lectures at George Washington University, wrote the "Camp David Profiles" of Anwar Sadat and Menachem Begin which were said to have significantly influenced President Carter's strategy for negotiations at Camp David in 1978.
During the Cold War years, the centre was particularly interested in key Soviet figures, says author Ronald Kessler. "At that time every aspect of a Soviet leader's public appearances was scrutinised.
"Agents would use any means at their disposal to get medical information on heads of state," he says.
"They would even try to get samples of human waste to analyse. If a political leader was in town, they would try to raid their toilets."
Mr Kessler says CIA agents would try to "buy off" members of the head of state's entourage to glean information.
In other instances, he says, they would examine their appearance on TV.
One subject who has been scrutinised this way is al-Qaeda figurehead Osama Bin Laden. His tapes will have been scoured not only for clues to his whereabouts but to his state of health.
Agents would have studied his appearance and mannerisms for any indications of possible psychological irregularities and the extent of his reported ailments.
Nowadays, it appears psychological profiling is no longer as important as it used to be, with many people questioning whether psychological insights are able to offer significant guidance for understanding world figures.
"It used to be very much in vogue," says Mr Kessler, "but, while to some extent, it is still used, it is not seen as that valuable any more."
But medical profiling is still going strong. According to one job advertisement on its website, the "CIA's Directorate of Intelligence (DI) is looking for physicians to produce assessments for senior policymakers on global health issues, such as disease outbreaks, and the health of foreign leaders".