A new study has found that some Vietnam veterans still have symptoms of post-traumatic stress disorder (PTSD) decades after the end of that divisive war.

The Vietnam War ended 40 years ago, but its effects on the mental health of veterans still lingers.

This has not only surprised some experts, but it has raised concerns among health professionals about the ongoing care of these aging veterans.

The study also highlights the difficulties that may be faced by younger military personnel serving overseas if they don’t make use of effective treatments sooner.

One mental health problem that is common among veterans of all ages is post-traumatic stress disorder (PTSD) — a condition that can occur after any traumatic event.

According to a new study, 271,000 Vietnam veterans who served in the middle of the war zone currently have PTSD or meet some of the criteria for its diagnosis.

“An important minority of Vietnam veterans are symptomatic after four decades, with more than twice as many deteriorating as improving,” wrote the authors of a paper published online July 22 in JAMA Psychiatry.

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The authors estimate that, of the veterans who served in the war zone, 4.5 percent of men and 6 percent of women currently have PTSD.

When veterans who met some, but not all, of the diagnostic criteria were also included, these numbers increased to almost 11 percent for men and almost 9 percent for women.

The current study is a follow-up to a similar one done 10 years after the end of the Vietnam War — between 1984 and 1988.

Over the decades between these two studies, 16 percent of the war-zone veterans experienced an increase of more than 20 points on a test used to measure PTSD symptoms. Around 8 percent of veterans reported a similar drop in symptoms.

Since that initial study, one-quarter of the veterans who participated have died. This time around, 1,450 veterans underwent at least one PTSD evaluation for the new study.

“The sobering findings [of this study] tell us as much about the Vietnam generation as about the lifelong impact of combat service in general, relevant to all generations,” wrote Dr. Charles Hoge, of the Walter Reed Army Institute of Research, in an accompanying editorial.

The new study also found that around one-third of war-zone veterans with current PTSD also had major depression. This is just one of the conditions that is likely to occur alongside PTSD.

“One of the issues that often comes up for people with PTSD is substance-abuse problems,” said Elliot Weiner, Ph.D., a clinical psychologist and director of the trauma and PTSD program at CBT/DBT Associates in New York, “which in many situations are people’s efforts to self-medicate through drugs or alcohol.”

Together PTSD, depression, and substance abuse problems can disrupt the lives of veterans, including their relationships with their partners and family.

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Although the way PTSD is assessed has changed since the 1980s, the authors also included one specific measure of PTSD symptoms that had also been used in the initial study.

This measure “was used in precisely the same format at both time points, allowing for an accurate estimate of changes and PTSD symptom severity across 25 years,” study author Dr. Charles Marmar, a psychiatrist at the New York University Langone Medical Center, wrote in an email.

The way mental health conditions in the military are addressed has also changed since the end of the Vietnam War.

“When Vietnam veterans came back from Vietnam, we didn’t call what they were experiencing PTSD,” said Paula Schnurr, Ph.D., executive director of the Department of Veterans Affairs’ National Center for PTSD. “We didn’t put that label in place until 1980, even though the symptoms had been observed in numerous wars before this.”

For Vietnam veterans, that meant they had to make do with the treatments that were available at the time.

“Many Vietnam veterans did face the problem of coming back and being misdiagnosed and being misunderstood,” said Schnurr.

Since the 1980s, more effective treatments for PTSD have been developed. However, veterans — of all ages — may not be accessing these frequently enough.

“Although screening and treatment services are unparalleled now compared with the Vietnam era,” wrote Hoge, “challenges persist, including low use of mental health services for those most in need and high rates of treatment dropout.”

The nature of PTSD itself may contribute to the difficulty in connecting veterans with screening and treatment programs.

“One of the characteristic experiences of people with PTSD is that thinking about and remembering what they’ve experienced can be extremely upsetting,” said Weiner, “and they’ll do basically whatever they can do to avoid thinking about and talking about it.”

As a result, veterans may avoid seeking help, drop out of treatment early on, or not speak openly when they do go.

The VA has been stepping up its efforts recently to destigmatize mental health problems in the military. This includes websites that share stories of veterans who have been helped by mental health treatments. Among them are Make The Connection and About Face, which deals specifically with PTSD.

Many of these efforts use technology like web conferencing and PTSD apps to reach out to veterans. But they are not aimed solely at younger veterans of the recent conflicts in Iraq and Afghanistan — 11 to 20 percent of whom have PTSD in any given year.

Even when older veterans have tried treatment programs before, the newer options may still reduce their PTSD symptoms.

“In looking at some of these newer therapies — prolonged exposure and cognitive-processing therapy — by and large what we see is Vietnam veterans respond as well as the younger veterans,” said Schnurr.

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