By Maria A. Morgan, Ph.D., MPS
Oct. 19, 2022

U.S. Marine Corps Photo by Cpl. Lydia Gordon

Imagine you just enlisted in the military. You're young, in peak physical condition, and eager to test your mettle in defense of your country. Your family is cheering you on (though Mom's a bit weepy), your school buddies just threw you a going away party, and you are exhilarated. Hoorah! And then you're in boot camp. The physical challenges are fierce and exhilarating, but sometimes you're not sleeping more than five hours a night, and you're beginning to worry about deployment and what your friends back home are doing without you. Anxiety creeps in, maybe mixed with depressed mood, and you nearly yelled at your drill instructor. You wonder what's going on with you.

Most likely, you're doing what a lot of people do when confronted with stress: reacting, adjusting, and adapting. It is a routine and necessary part of life. However, when the capacity to adapt to great stress is overwhelmed, some people develop adjustment disorder. Adapting to some of the unique psychosocial and physical demands of military life can be an immense stressor for some service members. Adjustment disorder is the most commonly diagnosed mental health disorder in active duty service members. It accounted for nearly one third (30.8%) of incident mental health diagnoses in the period from 2016 to 2020, far more than post-traumatic stress disorder (7.7%), anxiety (16.7%), or depressive disorders (16.5%).¹ It is common throughout the military, both in military trainees recommended for separation due to mental health issues² as well as in previously deployed populations.³

What is adjustment disorder?

One of the defining features of adjustment disorder is that the symptoms arise in response to an identifiable stressor that occurred sometime within the prior three months.⁴ The symptoms represent significant emotional distress that is out of proportion to the reaction one would typically expect from a stressor of that severity. This is usually in the form of anxiety and/or depressed mood. However, if the combination of symptoms and disorder features meet the criteria for another disorder, that disorder has to be diagnosed instead of adjustment disorder. Symptoms may also be expressed behaviorally, such as having problems functioning socially or professionally (or in other important areas). Given that the symptoms are in direct response to a specific event, they are expected to go away soon after the stressor or its consequences end, usually fairly quickly and no more than six months later. The stressor can be almost anything if it prompts the above symptoms. It may be a single event, such as being in a fender bender or starting a new job (think of our new military enlistee above). Or it may be chronic, such as mounting financial debt or developing a painful disease. The stressor can also be as severe as that required for a PTSD diagnosis, as long as the other criteria for PTSD are not met.

You may have noticed that there is a lot of flexibility in the criteria for an adjustment disorder diagnosis, both in the symptoms and the stressor. What exactly are the symptom requirements, and are you sure it isn't an anxiety or depressive disorder? Or even a pretty normal response, given the circumstances? How do you know it isn't the first inklings of PTSD, given a stressor of such severity? Researchers and clinicians have noticed this as well, and there has been a big push in the past decade to more precisely characterize the disorder as well as to develop screening and assessment tools. However, there's still a lot we don't know, such as who is most likely to develop adjustment disorder, how severe it will be, and what the disorder's typical course is.

What is the Psychological Health Center of Excellence doing?

Military service members may be exposed to periods of high or chronic stress, particularly during periods of extended deployments. In 2018, we conducted a research gaps analysis on adjustment disorder to figure out what research needed to be done to best address the psychological health needs of service members.^5-6 Our research recommendations addressed topics in the areas of epidemiology, etiology, prevention, screening, treatment, and services research. PHCoE undertook conducting some of this research in the form of systematic reviews and health services utilization data research. Here's a glimpse at what we found.

Evidence Synthesis and Dissemination

Predictors of adjustment disorder—a systematic review. We initially identified thousands of potential studies and narrowed them down to a final 70 that examined 13 theoretically-derived and predefined predictors of adjustment disorder.⁷ We found that female gender, younger age, unemployed status, stress, physical illness and injury, low social support, and a history of mental health disorders predicted adjustment disorder. However, most studies compared people with adjustment disorder to people without mental health disorders. We concluded that research is still needed to identify those risk factors that specifically predict adjustment disorder and differentiate it from other mental health disorders.

Prognosis of adjustment disorder—a systematic review. Here, we looked at studies that examined people who already had an adjustment disorder and asked what its diagnostic course and other outcomes were.⁸ For example, will it resolve without lingering issues or develop into another mental health disorder? Do patients who receive treatment respond well? We found, based on limited research, many people with an adjustment disorder continued to have a mental health disorder months to years later, and they were at increased risk for later development of various health issues (e.g., cancers, infections). On the whole, however, they tended to have greater symptom improvement in response to treatment than did people with other disorders. We concluded that this line of research is in the nascent stage, as most of the studies were not designed to examine explicitly the course of adjustment disorder.

Health Services Population Research

In these studies, we used large databases to address our questions. These included personnel data (e.g., demographics and military characteristics), medical care data (e.g., diagnoses received during outpatient care and hospitalizations), and data about deployments and military separation.

Factors associated with early separation. In order to better understand the association of adjustment disorder with military career, we first looked at two things that might be related to separation from military service: mental health history and when the service member receives their first adjustment disorder diagnosis.⁹ We found that nearly half (46%) of service members with an adjustment disorder was previously diagnosed with another mental health disorder and had an increased risk of separation. We also found many (19%) first-time adjustment disorder diagnoses were received during the first six months of service and significantly increased the likelihood of early separation, with a 60% probability of separating within two years of the diagnosis. We concluded that adjustment disorder was associated with a shortened military career, particularly when received early in service.

The course of adjustment disorder. In this study, our primary aim was to examine the diagnostic course of an initial adjustment disorder diagnosis (e.g., does it develop into another mental health disorder or get better?).¹⁰ We found that 44% of adjustment disorder patients no longer had a mental health disorder six to 15 months later; however, nearly a quarter (24%) developed another mental health disorder, and an additional 9% continued to have adjustment disorder. Deployment prior to the initial adjustment disorder diagnosis was the biggest predictor of developing another mental health disorder. Not surprisingly, patients who went on to developed another mental health disorder separated at the fastest rate. We concluded that adjustment disorder, in a large minority of cases, can have an enduring impact across the military career.

In sum, PHCoE has been working hard to address the psychological health needs of our service members. Adjustment disorder is just one of the topics we are researching to help improve medical readiness. By developing a better understanding of mental health concerns and how they are affecting service members, our findings can help inform treatment and policy. For example, as an early indicator of more severe psychiatric outcomes, an initial adjustment disorder diagnosis may signal an opportunity for early intervention and screening, particularly in service members with a history of deployment.

References

1. Armed Forces Health Surveillance Division. (2021). Update: Mental health disorders and mental health problems, active component, U.S. Armed Forces, 2016-2020. MSMR, 28, 2–9.
2. Englert, D. R., Hunter, C. L., & Sweeney, B. J. (2003). Mental health evaluations of U.S. Air Force basic military training and technical training students. Military Medicine, 168(11), 904–910.
3. Campbell, M. S., O’Gallagher, K., Smolenski, D. J., Stewart, L., Otto, J., Belsher, B. E., & Evatt, D. P. (2021). Longitudinal relationship of combat exposure with mental health diagnoses in the military health system. Military Medicine, 186(Supplement 1), 160-166.
4. American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed). American Psychiatric Association, Washington, DC.
5. Psychological Health Center of Excellence. (2019). Prioritized Research Gaps Report for Adjustment Disorders CY 2018. https://www.health.mil/Reference-Center/Publications/2021/04/29/PHCoE-Research-Gaps-Report-for-Adjustment-Disorders_2018_508. Accessed 10-17-2022.
6. Morgan, M. A., Kelber, M. S., Workman, D. E., Beech, E. H., Garvey Wilson, A. L., Edwards-Stewart, A., Belsher, B. E., Evatt, D. P., Otto, J., Skopp, N. A., Bush, N. E., & Campbell, M. (2021). Adjustment disorders: a research gaps analysis. Psychological Services. https://doi.org/10.1037/ser0000517.
7. Kelber, M. S., Morgan, M. A., Beech, E. H., Smolenski, D. J., Bellanti, D. M., Galloway, L., Ojha, S., Otto, J. L., Garvey Wilson, A. L., Bush, N., & Belsher, B. E. (2022). Systematic review and meta-analysis of predictors of adjustment disorders in adults. Journal of Affective Disorders, 304, 43-58. https://doi.org/10.1016/j.jad.2022.02.038.
8. Morgan, M. A., Kelber, M. S., Bellanti, D. M., Beech, E. H., Boyd, C., Galloway, L., Ojha, S., Garvey Wilson, A. L., Otto, J. L., & Belsher, B. E. (Under review, 2022). Outcomes and Prognosis of Adjustment Disorder in Adults: A Systematic Review.
9. Morgan, M. A., O’Gallagher, K., Kelber, M. S., Garvey Wilson, A. L., Belsher, B. E., & Evatt, D. P. (2022). Adjustment Disorder in US Service Members: Factors Associated With Early Separation. Military Medicine. https://doi.org/10.1093/milmed/usac008.
10. Morgan, M. A., O’Gallagher, K., Kelber, M. S., Garvey Wilson, A. L., & Evatt, D. P. (Under review, 2022). Diagnostic and Functional Outcomes of Adjustment Disorder in U.S. Active Duty Service Members.

Maria A. Morgan, PhD, MPS, is an ICF contractor supporting PHCoE, Defense Health Agency. Her doctorate is in experimental psychology/behavioral neuroscience and her master’s degree is in clinical psychological science. She has been supporting PHCoE as a psychological health researcher for over five years.