More than 75 percent of wounded veterans are dealing with post-traumatic stress disorder, according to the latest annual survey sponsored by the Wounded Warrior Project.

Steve Nardizzi, chief executive officer for the organization, said more than 23,000 veterans registered as members of Wounded Warrior Project completed the survey, making it the largest collection of data on the post-9/11 generation of wounded vets yet collected.

"Our annual survey shows that this generation of injured veterans continue to struggle with the invisible wounds of war, including PTSD and TBI [traumatic brain injury], and the challenges are not getting better with time," he said.

Pentagon figures published in an August 2015 Congressional Research Service report indicated that more than 300,000 service members suffered a TBI from 2001 through the first quarter of 2015, of which nearly 8,000 were severe or penetrating TBI.

The findings also make clear, he said, that the country needs to make a lifetime commitment to support the wounded, their families and caregivers.

In releasing the latest survey's findings, Nardizzi also announced a new $100 million program that WWP is backing with four major medical centers to help ensure that veterans get the mental health assistance they need.

In the survey, more than half of all respondents, or 53.6 percent, said they sought professional help with issues of stress, emotional difficulties, drugs, alcohol or family issues.

But about a third of those, or 35 percent, reported having difficulty getting mental health care, put off getting the help or did not get the care they needed.

"Year over year, the [survey] shows mental health issues are becoming more prevalent in veterans who served in Iraq and Afghanistan," he said. "Of greater concern, access to quality mental health care is not keeping up with the demand."

The WWP serves more than 80,000 wounded service members and more than 13,000 family members and caregivers, the organization said.

Given the number of wounded vets reporting they could not get the mental health care they sought, the Wounded Warrior Project will begin a new program next year called Warrior Care Network. The group says it's a "first-of-its-kind medical care network" to connect wounded vets and their families with world-class, personalized mental health care.

Nardizzi said the network is being funded with a $100 million investment by the WWP and academic medical center partners -- Emory's Veterans Program at Emory University in Atlanta; Massachusetts General Hospital Home Base Program in Boston; Operation Mend Program at UCLA Health in Los Angeles; and Road Home Program at Rush University Medical Center in Chicago.

"This collaboration will help address the problem, but it is just a start," he said.

Among other findings in WWP's survey of "Alumni" -- the term it uses for registered members: •Some four out of 10 vets -- 43 percent -- reported difficulty falling asleep or slept too much nearly every day during the two weeks prior to taking the survey. •About two-thirds, or 66.4 percent, said they had nightmares linked to a frightening, horrible or upsetting military experience •Three out of four of those same veterans -- 75.5 percent -- said they recalled the experience when they did not want to. •More than half of all respondents, 53.6 percent, said they sought professional help with issues of stress, emotional difficulties, drugs, alcohol or family issues. •About a third, or 35 percent, reported having difficulty getting mental health care, put off getting the help or did not get the care they needed.

In some areas, the news was better. Among WWP respondents, 16.6 percent reported being unemployed in 2015, down from the 19.7 rate reported in the Wounded Warrior Project's 2014 survey.

On the education front, 26.5 percent of respondents said they hold a bachelor's degree or better. In 2014, the percentage was 24.5 percent.

Additionally, more than two-thirds -- 67.5 percent -- said they were seeking a bachelor's degree or better, as compared to 65.6 percent a year ago.

Bryant Jordan can be reached at bryant.jordan@military.com. Follow him on Twitter at @bryantjordan.