The diagnosis was included in a document dump orchestrated by the defense, which has lobbied for the release of more information about Bergdahl to educate the public about his case.
"The Bergdahl Docket is simply a repository for case documents. It will not include commentary and there will be no provision for posts or comments by third parties," the site says. "We hope it will be useful to the public and the news media."
Among the documents is a 371-page transcript of a major general's wide-ranging interview
with Bergdahl in which the soldier describes his motivation for leaving his post in Afghanistan in June 2009.
Bergdahl, 29, is facing a court-martial, charged with desertion
and misbehavior before the enemy.
Army evaluation: He also has PTSD
According to an Army Sanity Board evaluation, Bergdahl had schizotypal personality disorder "at the time of the alleged criminal conduct" and now also has post-traumatic stress disorder.
"Though Sgt. Bergdahl did have a severe mental disease or defect at the time of the alleged criminal conduct, he was able to appreciate the nature and quality and wrongfulness of this conduct," said a July 27, 2015, memorandum from the sanity board.
The memo said he does not currently suffer from a mental disease that would render him unable to understand the proceedings.
Those with schizotypal personality disorder are "often described as odd or eccentric and usually have few, if any, close relationships," according to the Mayo Clinic
. "They generally don't understand how relationships form or the impact of their behavior on others."
People with this condition have persistent social anxiety and often incorrectly interpret events, "including feeling that external events have personal meaning," the Mayo Clinic website says.
The condition is different from schizophrenia, described as "a severe mental illness in which people lose contact with reality," the site says. "While people with schizotypal personalities may experience brief psychotic episodes with delusions or hallucinations, they are not as frequent, prolonged or intense as in schizophrenia."
In an August 2014 interview with Maj. Gen. Kenneth Dahl
, Bergdahl said he'd had adjustment and emotional problems.
According to the transcript, he traveled to Paris to join the French Foreign Legion because it sounded adventurous but was turned down because of his vision.
He later enlisted in the Coast Guard but said he was released during basic training with an "uncharacterized discharge" after a panic attack.
He was relieved to leave the Coast Guard but disappointed with himself because "the information I was getting from my family, especially my dad, was that I can't succeed in anything, that I am a failure," Bergdahl said.
He explained that his strict, home-schooled upbringing in rural Idaho contributed to his antisocial tendencies.
"I am an introvert," he said, according to the transcript. "I have to actually put a lot of effort into being a conversationalist in social environments. I can't go to parties because that just drains me. It takes a lot of effort to carry on in a regular conversation with somebody."
But he credits dance lessons with helping him develop relationships.
"One of the reasons why I was focusing on dancing was because that put me in an environment that forced me to actually interact on a social level that I was never used to," he said. "Because growing up in the household that I grew up in girls didn't exist to me until I turned 17. ... I understood that I needed to work on that."
Bergdahl's experience in the Coast Guard didn't keep him from enlisting in the Army. He said he admired the military, grew up with guns and wanted eventually to join the Special Forces.
But when he got to Afghanistan, he was upset with the attitude of some of his fellow soldiers and the leadership of his superiors, he said.
'I had to do something'
In the transcript, Bergdahl explains why he left his post and walked off his base in Afghanistan. This reasoning was revealed
in the first episode of season two of the podcast "Serial,"
which has focused on Bergdahl's case.
Bergdahl said he hoped his departure would provoke investigations by creating a crisis. Just airing his complaints with superior officers wouldn't have gotten any response, he said.
"I was seeing things heading in a very dangerous direction," he said. "So, I had to do something. It had to be me doing it. And so I came up, happily with my ignorance of a young -- from a young man's mind and my imagination, I came up with a fantastic plan."
Bergdahl said he knew he'd be charged but said, "What they were going to be forced to do is, they were going to be forced to adjust my platoon's command."
The Taliban captured Bergdahl in June 2009, holding him captive until a prisoner swap for five members of the militant group
in May 2014.
Last month, a judge in the court proceedings involving Bergdahl issued a stay of proceedings
, essentially putting the court-martial on hold. The stay is in place until an appeals court can resolve a dispute involving the sharing of classified evidence with Bergdahl's defense team.
The documents included on the defense site were first distributed to PBS and The New York Times.