SAN ANTONIO — The commanders of Sgt. Bowe Bergdahl’s platoon, company and battalion testified Thursday that his disappearance from his post in Afghanistan six years ago put a strain on their forces and put his fellow soldiers in danger.

The testimony came during a hearing where an attorney for Bergdahl, Lt. Col. Franklin Rosenblatt, said Bergdahl had been discharged from the U.S. Coast Guard because of psychological problems and an Army psychiatric board later concluded he had a “severe mental defect.” Rosenblatt’s comments about Bergdahl’s mental health history came as the lawyer questioned a witness called by military prosecutors.

Attorneys for Bergdahl, who is charged with desertion and misbehavior before the enemy, will get to present their own evidence and call witnesses today on the second day of the hearing to determine whether Bergdahl should face a court-martial. His lead attorney, Eugene Fidell, said after Thursday’s proceedings that he would call four witnesses, though he declined to say if Bergdahl would be one of them.

Military prosecutors focused on trying to substantiate the misbehavior charge, which carries a possible life sentence and which would require them to prove that Bergdahl’s actions put other soldiers in harm’s way.

Capt. John Billings, who led Bergdahl’s platoon, described the 45-day search for the Idaho native as grueling, saying soldiers got little food or sleep and endured temperatures in the high 90s.

“Physically, mentally I was defeated,” Billings said, adding that he felt like he had “failed” his men.

Bergdahl spent five years as a Taliban captive until he was exchanged last year for five Taliban commanders who were being held at the U.S. detention center at Guantanamo Bay, Cuba. The prisoner swap was sharply criticized by many Republicans and some Democrats, who said it was politically motivated and counter to the U.S. policy against negotiating with terrorists.