Work-focused Versus Generic Internet-based Interventions for Employees With Stress-related Disorders - a Randomized Controlled Trial

Introduction Work is an important part of life, contributing to both health and wellbeing for many employees. However, in recent years, stress-related disorders have received more attention, with an increasing prevalence within the working population. For example, every fourth employee within the European union has experienced stress during most of their working day. Long-term exposure to stressors, such as job strain or interpersonal conflicts, without sufficient recovery, can lead to a dysregulation in the allostatic system, "allostatic load", which constitutes the fundamental features in the development of chronic stress or stress-related disorders. The major diagnostic systems, Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and International Statistical Classification of Diseases and Related Health Problems (ICD-10 and 11) includes sections regarding stress-related disorders. However, the DSM and ICD systems lack an established terminology and criteria for stress induced fatigue and exhaustion. Consequently, the diagnosis "Exhaustion disorder" (ED) was introduced in the Swedish version of the ICD-10 in 2005. ED is manifested by symptoms of extensive mental and physical fatigue, lack of initiative and endurance and prolonged recovery after mental or physical effort. Later international publications have suggested that ED is not an exclusive Swedish condition. Few studies have been published regarding the prevalence of ED, but in a recent study, based on physician-based diagnosis in 3406 participants, 4.2% reported ED.

In addition to stress-related disorders and well-known health implications, such as coronary artery disease, lowered immune functioning, anxiety, depression and insomnia, chronic stress have been associated with impaired work functioning and problems in work participation such as sickness absence and long-term sick leave. In Sweden, for example, stress-related disorders accounted for one fifth of all sick leave during 2019. Decreased work participation is problematic as it has direct effects on people's well-being and leads to immense costs for society. For instance, the total estimated annual costs for work-related stress observed in seventeen OECD countries is considerable, ranging from US $221 million to $187 billion. Given these rising costs, it is not surprising that many policy makers view stress as a major public health issue and are seeking advice on the types of interventions that may be effective.

During the last decades, psychological interventions have been developed in order to increase the individual's psychological resources and resilience to stress. Evidence suggest that stress management interventions are effective in reducing stress in the working population. These results apply to controlled studies targeting general and milder forms of stress-related ill health. However, considering clinical samples, interventions has been less successful, with small effect sizes.

Traditionally, psychological treatments for stress and common mental disorders have not explicitly focused on work-related aspects, such as reducing sickness absence (SA). Recent evidence suggests that psychological interventions are slightly more effective than treatment-as-usual in reducing sickness absence (small effect sizes). However, it is still uncertain what moderates these effects. There are some indications that work directed interventions in combination with psychological treatment are effective with respect to return-to-work (RTW) for those absent with common mental health problems. In a quasi-experimental study by Lagervelt and colleagues comparing CBT to work-focused CBT, full RTW occurred 65 days earlier and partial RTW 12 days earlier in the work-focused CBT group. A significant decrease in mental health problems was equally present in both conditions. These results suggest that by integrating work-related aspects early into the treatment, problems with sickness absence and long-term sick leave can be reduced.

Despite the well-documented efficacy of stress management interventions, and some promising results of work-focused interventions, the range of interventions are not proportionate to the needs among distressed employees. This clarifies the need to further develop and evaluate work directed interventions that are accessible to the working population.