A 6,000 page report from the Senate Intelligence Committee reached the conclusion "that harsh interrogation measures used by the CIA did not produce significant intelligence breakthroughs." Not surprising - Republicans on the committee refused to participate in the investigation leading to the report. Although, it would appear Sen. John McCain did participate.
"Sen. John McCain (Ariz.), who was a prisoner of war in Vietnam, issued a statement saying that the committee’s work shows that “cruel” treatment of prisoners 'is not only wrong in principle and a stain on our country’s conscience, but also an ineffective and unreliable means of gathering intelligence.'” [Report finds harsh CIA interrogations ineffective].
It is difficult to grasp that reasonable and rational people could conclude that torture and interrogation techniques just this side of torture could produce reliable information.
But don't ever expect to read any significant portion of the report. Procedures requires the opportunity for the administration and the CIA to review and comment. The Washington Post notes that "[i]t could be months, if not years, before the public gets even a partial glimpse of the report or its 20 findings and conclusions."
Democracy at work.