Here is an important, and somewhat hard to read, article on the lasting psychological damage from US torture programs.
Before the United States permitted a terrifying way of interrogating prisoners, government lawyers and intelligence officials assured themselves of one crucial outcome. They knew that the methods inflicted on terrorism suspects would be painful, shocking and far beyond what the country had ever accepted. But none of it, they concluded, would cause long lasting psychological harm.
Fifteen years later, it is clear they were wrong.