The screams of agony from the soldier echoed through the ballroom-turned-theater, forcing a hushed whisper among those witnessing his sudden break with reality.

He was no longer with his wife, seated beside him on the stage; no longer with his comrades. In his mind, he was back on the battlefield, killing his enemy — the price of years of combat stress from witnessing war's horrors.

In this "Theater of War," the wounds date back millennia and the words spoken by actors are translated from Greek, but they speak to Iraq and Afghanistan combat veterans and the doctors and therapists who treat them.

"I wanted to keep the pain to myself, son, but now it cuts straight through me. Do you understand? It cuts straight through me," the lead character in the play "Philoctetes" tells a comrade.

Those hidden wounds and their effect on family members and caregivers were the focus of the Greek readings at a three-day combat stress conference hosted by the Marine Corps that addresses post-traumatic stress disorder, anxiety and depression brought on by combat.

Just like the characters in the tragedies of Sophocles' "Ajax" and "Philoctetes," many of the Marines and sailors in the audience Wednesday night know the damage isn't always on display.

"I found that even 2,500 years ago Sophocles was using words like 'shell-shocked' and 'the thousand-yard stare.' Those are things that you hear today," said retired Lt. Col. Jay Kopelman, who fought in the fierce Iraq battle of Fallujah in November 2004.

"I know it's a bit odd to have Greek plays read to a conference of military people," said actor David Strathairn, best known for his Oscar-nominated role in "Good Night, Good Luck," who read the role of Philoctetes. "But you read these plays and you understand they are the first investigations into the condition of war in Western civilization."

Roughly 40,000 troops have been diagnosed with PTSD since 2003, making identifying and treating troops a priority. Earlier this year, Defense Secretary Robert Gates urged troops to get psychiatric counseling for wartime mental health problems, saying it wouldn't count against them if they apply for national security clearances for sensitive jobs.

"I don't know if the readings are going to get anyone to admit they have a problem. My goal is to open up a space for dialogue," said Bryan Doerries, who directed and translated the ancient plays.

Doerries was inspired to produce the performance by Dr. Jonathan Shay, author of the psychology book "Achilles in Vietnam," who took the position that Greeks used theater as a way to reintroduce combat veterans into society through the plays of Sophocles and others.

"We know that Greek drama was theater for combat veterans by combat veterans," Doerries said.

In the first-of-its kind readings for military personnel, Doerries said he selected the two plays because they were textbook cases of PTSD, even though the Greeks didn't have a term for it.

In Sophocles' "Ajax," the play follows the story of a combat veteran who slips into depression and attempts to kill his commanding officer only to be shamed by his actions and later have his wife and comrade try to talk him out of suicide.

"Philoctetes" tells the story of a wounded soldier left behind by his army, which then returns for him in the last year of the Trojan War. But Philoctetes struggles with the emotional trauma of accepting medical care from an army he longer trusts.

To make the plays more palatable to a modern audience, Doerries updated the language. But some of the signature lines in "Ajax" that describe his mental state translated through the ages to the more than 300 people in the audience.

Some women in the audience nodded their heads when Ajax's wife, played by stage actress Heather Raffo, intoned: "A divine madness poisoned his mind, tainting his name during the night."

Each 40-minute reading was met with a standing ovation, and a nearly two-hour discussion followed with Marines and their wives lining up to share their stories and their take on the Greek tragedies.

Kopelman, who wrote the memoir "From Baghdad with Love: A Marine, the War and Dog Named Lava," said he was also taken by a scene in "Philoctetes" where two soldiers bond over their dead comrades.

"That's something all warriors can relate to," he said.

Retired Navy Capt. Bill Nash, a psychiatrist who was embedded with troops in 2004 in Iraq, said the story of Philoctetes brought back memories of a counseling session with a Navy corpsman who suffered from PTSD brought on by a combat-related experience.

Nash said the corpsman had promised a scared, young Marine private that he would make sure to look after him during the battle of Fallujah. The private was cornered by insurgents during house-to-house fighting and killed, calling out for the corpsman as he died.

The suffering Ajax's wife endured while coping with her husband's demons moved Marshele Carter Waddell to tears. Waddell is the mother of a Marine and wife of a Navy SEAL diagnosed with PTSD in 2005 after multiple deployments.

"I don't think much has changed at all," she said of the plays' relevance today. "The war came home with my husband all four times."