The witnesses at the sentencing hearing painted a picture of Bergdahl's life before he enlisted and emphasized his contributions since he was returned in a prisoner swap.
Bergdahl pleaded guilty October 16 to desertion and misbehavior before the enemy. He faces up to life in prison for his desertion.
Hours after he deserted his outpost in Afghanistan in 2009, he was captured by the Taliban. After five years in captivity, Bergdahl was released in a controversial prisoner swap in exchange for five Guantanamo Bay detainees.
Dr. Charles Morgan, a forensic psychiatrist and professor at the University of New Haven and Yale University, testified Wednesday that Bergdahl suffers from numerous mental illnesses, including schizotypal personality disorder and post-traumatic stress disorder, as well as social anxiety/phobia and cognitive deficits.
Symptoms of schizotypal personality disorder include brief psychotic episodes that "are not as frequent, prolonged or intense as in schizophrenia," according to the Mayo Clinic.
Morgan said he interviewed Bergdahl's friends and family and did extensive testing on Bergdahl, including psychiatric evaluations, stress exams and neurological psychological testing. Based on the results, Morgan said Bergdahl was suffering from schizotypal personality disorder and PTSD before he enlisted in the armed forces, adding he "falls clearly into the profile" of someone who had schizotypal personality disorder by the time he enlisted.
The social anxiety/phobia and cognitive deficits were also present before he enlisted, Morgan said.
As a child, Bergdahl faced a tense and sometimes scary household, Morgan said, pointing out that he hid from his father, who punched holes in the wall. He added that Bergdahl felt "dumb, inferior, worthless (and like a) failure in eyes of his father."
Bergdahl was "someone who had a number of factors that pointed to stress vulnerability before enlistment," Morgan said. He labeled Bergdahl's PTSD as "severe," saying his symptoms were "completely consistent" with the cluster of symptoms seen in people suffering from the disorder.
For people suffering from PTSD, "their war experience can make them clinically sicker," Morgan said. He added that "people who have been exposed to trauma" do not think the same way that those who haven't would think.
Analyst says Bergdahl debriefs 'were a gold mine'
Terrence Russell, an official with the Pentagon's Joint Personnel Recovery Agency who debriefs former captives and makes training manuals based on the debriefs, testified Tuesday that Bergdahl was "an extremely cooperative participant" and provided lots of information for survival, evasion, resistance and escape training.
"He (Bergdahl) understood it was important to give information so we could utilize it to help others," Russell said. "I can use this information to help train forces in the future.
"I need him now. I needed him three years ago when he returned. The info he can provide to us is critical to helping the fighting force."
Amber Dach, a government intelligence analyst, said he "was eager to help" and the debriefings were valuable.
"The debriefings from Sgt. Bergdahl were a gold mine," she said. "We were able to positively identify what a holding location would look like."
'I made a horrible mistake'
During his Monday testimony
, Bergdahl teared up, apologizing to service members who searched for him after he deserted. Several of the searchers
were injured, including one who suffered permanent brain damage.
"My words can't take away what people have been through," Bergdahl, 31, told an audience at his court-martial that spilled into an overflow room. "I am admitting I made a horrible mistake."
His lengthy testimony began after the presiding judge rejected his attorneys' request to dismiss the case over President Trump's criticism of him during his campaign for the White House.