Some people are concerned about Zubaydah's mental stability and how that has affected information he has given to interrogators. Ron Suskind noted in his book, "The One Percent Doctrine: Deep Inside America's Pursuit of Its Enemies Since 9/11" (2006), that Zubaydah was mentally ill or disabled due to a severe head injury. He described Zubaydah as keeping a diary "in the voice of three people: Hani 1, Hani 2, and Hani 3"—a boy, a young man and a middle-aged alter ego. Zubaydah's diaries spanned ten years and recorded in numbing detail "what he ate, or wore, or trifling things said." Dan Coleman, then the FBI's top al-Qaeda analyst, told a senior bureau official, "This guy is insane, certifiable, split personality." According to Suskind, this judgment was "echoed at the top of CIA and was briefed to the President and Vice President." Coleman stated Zubaydah was a "safehouse keeper" with mental problems, who "claimed to know more about al-Qaeda and its inner workings than he really did."