Waterboarded Prisoner Has Drowning Nightmares Two Decades Later, Doctor Testifies

She also suggested that traumatic brain injury discovered on an M.R.I. of Mr. Nashiri at Guantánamo was the result of his role as “a battlefield participant” with Osama bin Laden, rather than Dr. Crosby’s explanation that he was repeatedly punched in the head while in C.I.A. custody, and for a time lost his hearing.

One of Mr. Nashiri’s defense lawyers, Annie W. Morgan, who is a Defense Department employee, described Tuesday’s testimony as the first open-court airing in detail of some of the torture he underwent as a C.I.A. prisoner, both in Afghanistan and at a secret site in Thailand.

Mr. Nashiri knew in advance what would be discussed, and “wants people to know what America did to him,” Ms. Morgan said. Still, because of the material, she said, he voluntarily stayed away from the courtroom during his team’s “first chance in an unclassified setting to tell his story.”

His nausea on trips to court has been a source of dispute since before the coronavirus pandemic stalled proceedings. Military doctors have cast it as run-of-the-mill motion sickness. Dr. Crosby said it was triggered by memories of the confinement box when Mr. Nashiri was transported in a windowless van. It affects him less so, she said, when the prison staff members are “kind” and transport him to court in a small school bus with the windows uncovered.

To go to court, prison doctors have been giving Mr. Nashiri both an antihistamine, Meclizine, which makes him sleepy, and Adderall, to perk him up. On questioning from the prosecutor, Dr. Crosby said she would like to discuss the unusual combination with his prison doctor, the latest in a series of Navy officers on temporary assignment to the detention operation.

The prosecutor noted that, in court, Mr. Nashiri sometimes appeared to swagger. At his first court appearance in November 2011, he turned and waved toward the gallery, where reporters and family members of victims of the Cole attack were watching.

But Dr. Crosby said that he was frequently fearful of both real and imagined things, and cited examples. He is afraid that a tsunami or a hurricane will hit the base in southeast Cuba and that his guards will abandon him in his cell to drown. He also reported being assaulted by another former C.I.A. prisoner this year, which has left him “hypervigilant and frightened that something might happen to him.”