The 12-month course of ICD-11 adjustment disorder in the context of involuntary job loss

Background: After its redefinition in ICD-11, adjustment disorder (AjD) comprises two core symptom clusters of preoccupations and failure to adapt to the stressor. Only a few studies investigate the course of AjD over time and the definition of six months until the remission of the disorder is based on little to no empirical evidence. The aim of the present study was to investigate the course of AjD symptoms and symptom clusters over time and to longitudinally evaluate predictors of AjD symptom severity. Method: A selective sample of the Zurich Adjustment Disorder Study, N = 105 individuals who experienced involuntary job loss and reported either high or low symptom severity at first assessment (t1), were assessed M = 3.4 (SD = 2.1) months after the last day at work, and followed up six (t2) and twelve months (t3) later. They completed a fully structured diagnostic interview for AjD and self-report questionnaires. Results: The prevalence of AjD was 21.9% at t1, 6.7% at t2, and dropped to 2.9% at t3. All individual symptoms and symptom clusters showed declines in prevalence rates across the three assessments. A hierarchical regression analysis of symptoms at t3 revealed that more symptoms at the first assessment (β = 0.32, p = .002) and the number of new life events between the first assessment and t3 (β = 0.29, p = .004) significantly predicted the number of AjD symptoms at t3. Conclusion: Although prevalence rates of AjD declined over time, a significant proportion of individuals still experienced AjD symptoms after six months. Future research should focus on the specific mechanisms underlying the course of AjD.