Lourdes Health System is opening a 21-bed unit to treat active-duty military women with post-traumatic stress disorder and other behavioral illnesses.

Living Springs at Lourdes is scheduled to open this month at Lourdes Medical Center of Burlington County in Willingboro and will be only the fifth such center in the country and the only one on the East Coast, Lourdes officials said.

A ribbon-cutting is scheduled for Wednesday.

Alexander J. Hatala, president and chief executive of Lourdes, said in an interview Tuesday that Living Springs builds on an existing partnership for medical care at Joint Base McGuire-Dix-Lakehurst.

"We've had a great relationship with the military since 2001," Hatala said.

Post-traumatic stress disorder is a behavioral illness that can afflict people who have witnessed terrifying events, such as being shot at on a battlefield or seeing friends killed.

Women, who make up about 15 percent of the armed forces, are more likely to suffer post-traumatic stress disorder than men, in part because they are more likely to be sexually assaulted, according to the U.S. Department of Veteran Affairs.

Overall, 11 percent of veterans of the war in Afghanistan have post-traumatic stress disorder, and 20 percent of Iraqi war veterans have it, according to Veterans Affairs estimates.

Lourdes estimated 60 percent of Living Springs patients would be admitted for post-traumatic stress disorder.

The system will spend $1 million to refurbish a former pediatric unit and hire 30 people to staff it, Hatala said.

Mark Nessel, executive vice president and chief operating officer at Lourdes, said military officials had said they expected the unit, with three private rooms and nine semi-private rooms, to be filled to near-capacity all the time.

"They have patients ready to go as soon as we're open," Nessel said.