“The scientific literature on isolation, as well as my own research and experience, indicate that “long-term” exposure to precisely the kinds of conditions and practices that—based on the extensive number of documents that I have reviewed and many prisoner interviews I now have conducted—clearly currently exist in the PBSHU and clearly place prisoners at grave risk of psychological harm. This is true whether or not those prisoners suffer from a preexisting mental illness. It should be noted that “long-term” or “prolonged” exposure to prison isolation is generally used in the literature to refer to durations of solitary confinement that are much briefer than the amounts of time that Ashker class members have been subjected to it. For example, the American Psychiatric Association (APA) defined “prolonged segregation” as segregation lasting for four weeks or longer (which the APA also said “should be avoided” for the seriously mentally ill).12 Thus, Ashker class members have, as a group, been subjected to durations of isolated confinement that far exceed—by substantial orders of magnitude—the amounts typically reported in the literature, studied by researchers, and considered psychiatrically problematic.”

Professor Craig Haney, Expert Report in Ashker v. Brown