Risk of First Adjustment Disorder in U.S. Army Soldiers

Adjustment disorder is the most common mental health diagnosis in the U.S. military and one of the most common globally, yet its patterns and predictors are rarely studied. Identifying career phases and characteristics associated with increased risk of first adjustment disorder (AD) diagnosis among U.S. Army soldiers can inform targeted prevention and intervention efforts.

This longitudinal, retrospective cohort study analyzed data from the Study to Assess Risk and Resilience in Servicemembers-Longitudinal Study (STARRS-LS). Administrative medical and personnel records from active duty Regular Army enlisted soldiers (2015-19) were used to identify all 118,735 person-months with a first AD diagnosis and a representative, stratified probability sample of control person-months with no history of AD diagnosis (n = 316,275). Risk of first AD diagnosis was estimated as function of time in service, stratified by sex and occupation. Logistic regression examined socio-demographic, service-related, and mental health risk factors for first AD diagnosis during periods of greatest risk. This study was approved by the Institutional Review Boards of STARRS-LS collaborating institutions.

AD cases were 77.2% male, 54.9% ≤24 years old, and 51.0% White Non-Hispanic. For 63.7% of cases, AD was their first documented mental disorder during service. Of those, 25.5% had been diagnosed with a stressor or marital problem in the previous 12 months. Risk of first AD by time in service was bimodal, with elevated risk during the first 1-4 years ("early-career") and years 17-20 ("late-career"). This pattern was consistent across sex and occupational groups. Based on a sample size-adjusted alpha level, 12 of 13 multivariable risk factors were associated with early-career AD, whereas 7 of 13 were associated with late-career AD. Notable risk factors among early- and late-career soldiers were female sex (early-career: OR = 2.0; 95% CI = 1.9-2.0; late-career: OR = 1.4; 95% CI = 1.3-1.5), deployment status (early: never-deployed, OR = 2.0; 95% CI = 1.9-2.2, previously-deployed, OR = 1.6; 95% CI = 1.4-1.8; late: previously-deployed, OR = 1.7; 95% CI = 1.5-2.0), and recency of previous mental health diagnosis (early: past-month, OR = 3.7; 95% CI = 3.6-3.8; late: past-month, OR = 4.2; 95% CI = 3.9-4.5), stressor/marital problems (early: past-month, OR = 5.7; 95% CI = 5.5-5.8; late: past-month, OR = 4.1; 95% CI = 3.8-4.6), and postconcussive syndrome (early: past-month, OR = 3.0; 95% CI = 2.6-3.5; late: past 2-3-months, OR = 2.7; 95% CI = 1.5-4.8). Magnitudes of other significant ORs were more modest. Interactions indicated that associations of 9 risk factors differed for early versus late career soldiers.

First AD risk is highest among soldiers either beginning their Army careers or approaching retirement eligibility. Differences in risk factors across groups highlight the importance of considering distinct military and life experiences/stressors when attempting to target and tailor interventions for those at risk of AD.