The military’s health program falls significantly short in providing mental health care to active service members, according to a RAND Corp. study published Thursday.

The study focuses on post-traumatic stress disorder and depression, the two most common mental health conditions experienced in the armed services.

It finds some good news: The Military Health Services – which is operated by the U.S. Department of Defense and provides care to active soldiers – is effective at contacting soldiers diagnosed with one of the conditions. In addition, a vast majority of soldiers who get diagnosed with PTSD or depression receive at least one talk therapy session, the study finds. In that regard, it outperforms civilian health services.

But the system faces difficulties ensuring that patients continue with treatment – either by continuing to see a psychotherapist or following up with a doctor after being prescribed medication.

“It’s essential to provide excellent care for these service members because of how much we ask of them,” said Kimberly Hepner, the study’s lead author and a senior behavioral scientist at RAND.

The study examined medical records for close to 40,000 soldiers diagnosed with one of the two conditions between January and June 2012. It’s the largest ever assessment of mental health in the military, according to RAND, a nonpartisan research institute based in California. Of those, about 15,000 had PTSD, and about 30,000 had depression. About 6,000 had both.

After soldiers get their initial mental health visit, the next treatment steps are a different story, the study found. About one in three patients newly diagnosed with PTSD got the appropriate follow-up care after starting treatment – typically, that’s at least four visits to a psychotherapist within two months of being diagnosed. For soldiers with depression, less than a quarter of them completed those four visits.

Meanwhile, only about 40 percent of patients who were prescribed medication for one of those conditions followed up with a doctor afterward. Those visits are essential, Hepner said, because the physician can make sure patients take their medication and help them manage side effects. A physician’s involvement also ensures that medication doesn’t counteract any other prescription drugs the soldiers take.

“Service members received a tremendous amount of medical treatment,” she said. “That’s why it’s even more critical to make sure that it’s a successful experience.”

Because other studies use different metrics for diagnosing and treating mental health conditions, it’s hard to compare these results to those of civilian health systems, Hepner said.

Depending on the experiences soldiers have, military combat can contribute to mental health problems, according to the Department of Veterans Affairs. Meanwhile, research has found suicide attempts seem to be more common in soldiers than in civilians, though it can be difficult to compare. A 2015 study found about 377 out of an estimated 10,000 enlisted soldiers attempted suicide.

The RAND study, which was commissioned by the DOD, is only the first part of an overarching project to assess the quality of mental health care for soldiers. It doesn’t yet delve into questions like why these soldier-patients stop their therapy and medication – considering, for instance, that about 90 percent of those who are diagnosed with PTSD get at least one follow-up visit to therapy, and about 80 percent with depression do.

Potential explanations could include insufficient access to mental health professionals, said Joe Davis, a spokesman for Veterans of Foreign Wars. Many soldiers might also fear judgment from their peers for asking for help.

“It’s very easy for senior leaders to say there is no stigma, but far different on the ground at the small-unit level, where everyone relies on their buddy … and vice versa,” he said in an email.

Soldiers might also have been unhappy with the mental health care they got, he added, and therefore not return.

The shortage of mental health professionals is one of the biggest barriers to continuous mental health care, said Elspeth Cameron Ritchie, a former military psychiatrist. Since more soldiers have been deployed to Iraq and Afghanistan, the need for doctors has grown, she added.

Beyond questions of stigma and a shortage of providers, there could be an issue of appointments not being available at convenient times, Hepner said. “We ask a lot of service members, and they have a lot of demands on their jobs.”

Because soldiers travel a lot, it can be difficult for them to keep up good, continuous access to care, Ritchie said. That difficulty in finding time and flexibility can compound many soldiers’ reluctance to keep up with mental health care. Many, she added, worry about others’ perception if they are seen regularly visiting a psychiatrist.

“If you need to go to the doctor all the time, people will think, ‘Oh what’s wrong with that person?’” Ritchie said. “There’s a lot of talk about how we should treat this as a broken leg, and there shouldn’t be a stigma. But there is a stigma.”

The Defense Department’s action in commissioning RAND’s study is encouraging, Hepner said, because it suggests an active interest in trying to improve mental health care and access to it. DOD could build on efforts to publicly measure how good military, mental health providers are, she said. The department’s begun doing that, but Hepner said the public needs more information about quality of care. The RAND findings could have understated the difficulty of obtaining mental health care, Hepner added. RAND focused on patients who had been diagnosed with mental health problems, but it likely missed soldiers who either hadn’t seen a doctor at all or who had but hadn’t been diagnosed.

Even when they go to the best doctors, soldiers must ask for help, which can be difficult, Davis noted.

For instance, all the soldiers in RAND’s study had been identified as needing help. That makes it easier to connect them with care – which could have influenced the high proportion of soldiers who had their initial visit, Hepner said.

“The real risk here is the people we are not addressing,” she added.