Editor’s note: This article by Patricia Kime originally appeared on Military.com, a leading source of news for the military and veteran community.

Mental health disorders were the top reason that active-duty U.S. military personnel were hospitalized in 2023, a trend that began in 2009 but has shown signs of easing in the past three years, according to two new reports from the Defense Health Agency.

Musculoskeletal injuries remain the No. 1 reason service members visit a medical facility, but mental health conditions are most responsible for putting them in hospitals overnight and keeping them there, according to epidemiologists with the Armed Forces Health Surveillance Division, who reviewed all medical appointments and hospitalizations among troops in 2023.

Of the roughly 62,806 times active-duty service members were hospitalized in 2023, nearly one-third -- 31% -- were there for mental health treatment, with adjustment disorders and alcohol abuse as the top diagnoses for men, and adjustment disorders and major depressive disorder the main diagnoses for women.

While the median length of stay for a mental health issue was five days, some personnel stayed as long as 34 days, according to the June issue of the Medical Surveillance Monthly Report released Tuesday.

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The mental health of U.S. service members has been a major focus of Defense Department policy and health programs since the late 2000s, when the number of suicides began rising among not only the active-duty component but also in the Guard and reserves.

Prior to 2008, military service was a protective factor against suicide, with troops having lower rates than the comparable U.S. population. But since that year, suicide rates have risen steadily despite enormous efforts by the military services and DoD to prevent such deaths.

With mental wellness a key component of the Defense Department's suicide prevention strategy, the department needs to understand the scope of diagnoses and hospitalizations to formulate policy, the researchers said.

"An accurate estimate of the health status of the armed forces can be used not only for determining expected health care use and costs" and for prioritizing treatments, but also to evaluate treatment impact and cost effectiveness, they wrote.

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According to the reports, of the 14 million medical encounters troops had in 2023, counting appointments as well as hospitalizations, nearly 20% were for mental health -- an increase of 3% from 2018 that may be attributable to access to no-cost medical care and training requirements, the authors said.

However, in terms of overall encounters with medical personnel -- appointments and hospitalizations -- injuries remained the top reason why service members saw a doctor.

Injuries accounted for nearly one-quarter of all medical encounters by active-duty personnel last year, with back issues being the top complaint, followed by knee problems and arm and shoulder injuries.

Sleep disorders came in fourth, followed by other musculoskeletal problems. Anxiety, "ill-defined" symptoms, adjustment and mood disorders, and foot and ankle pain rounded out the top 10 reasons for troops to have contact with a provider in 2023.

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The authors noted that, given the connection between mental health and physical health, particularly regarding back pain, military providers should consider a holistic approach to treating service members, rather than compartmentalize their medical conditions and treat each one separately.

They urged military medical leadership to use "holistic, integrated approaches to care" that take into account the unique health challenges faced by service members in training and combat, as well as the "interplay between mili­tary and civilian health care systems," to "better meet the health needs of military personnel and veterans."

Maternity care -- labor and delivery or pregnancy-related complications -- was the second most common reason service members were hospitalized in 2023. Largely as a result of this care, the hospitalization rate for service women, who make up 19% of the force, was more than three times that of servicemen.

When removing maternity care from the equation, the hospitalization rate for women was still 33% higher than men, largely as a result of hospital stays for mental health disorders and genitourinary disorders, according to the report.

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The researchers noted that the Air Force and Space Force stood out in terms of hospitalizations, with pregnancy- and delivery-related conditions being the top reason airmen and Guardians were hospitalized. Mental health was the leading cause of hospitalization for the Army, Navy and Marine Corps.

"This pattern has been observed in recent years. Prior to 2020, pregnancy- and delivery-related conditions were ranked first for both Navy and Air Force active component members. Among all the services, the crude hospitalization rate for mental health disorders was highest among active component Army members," they wrote.

They noted that injury was the third leading reason for hospitalization across the services with the exception of the Air Force, where it was ranked fourth. Among the services, the Army had the highest hospitalization rate for injury followed by the Marine Corps.

In a bit of good news regarding the health of the force, hospitalizations for all major diagnoses declined from 2019 through 2023, and the crude rate – a simple measure of the total number of hospital admissions divided by the mid-year population that gives researchers a sense of general trends – was its lowest since 2014, according to the reports.

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In a separate report, the researchers analyzed the medical encounters and hospitalizations of Coast Guard members and saw similarities to the results of the Defense Department armed services, including injuries as the leading cause of all medical appointments or hospitalizations, and mental health accounting for the most days spent in the hospital, making up 55% of the 8,717 days active-duty Coast Guardsmen spent in the hospital.

The analysts said they perform this in-depth look into injury and illnesses among troops to help military and civilian DoD leadership understand the scope of the issues; provide information on the health of armed forces; and guide decisions on prevention and treatment, as well as effectiveness.

"Recent and accurate infor­mation on the scale of health disorders among service members, groups notice­ably at risk, and trends in their health statuses over time are critical data for policymakers," they wrote.