Abstract
Subsyndromal symptoms, or mild to moderate symptoms of depression, contribute more than any other health condition to absence from work. Mental illness is the leading cause of sickness absence and work incapacity in most developed countries, and depression is predicted to be one of the leading causes of work disability by 2020. Despite the high prevalence of mental health problems, in most workplaces mental health programmes are not available, and when such programmes are introduced, attention is seldom paid to documentation of the effects.
This thesis examines to what extent a mental health intervention in the workplace may contribute to improved mental health, and independent of the intervention, the longitudinal interrelations between selected factors are examined. More specifically: this thesis presents an evaluation of the Coping With Strain (CWS) course with focus on effects of the course on symptoms of depression, self-efficacy, self-esteem, and vitality. Furthermore, the prospective reciprocal associations between symptoms of depression, generalized self-efficacy and social support are examined.
The CWS course aims to empower participants, promote mental health, and reduce mental ill-health at an individual level. It is mainly based on principles adapted from Cognitive Behavioural Therapy (CBT). A central and important aim is to improve psychological resources and mastery, and reduce symptoms of depression.
The CWS course evaluated in this thesis was offered to all employees in four municipalities in Eastern Norway, and may be described as a universal intervention. However, in this PhD project, and consistent with ordinary practice in this kind of workplace intervention, only participants with minimal to moderate symptoms of depression were accepted onto the CWS course. In this project, 137 employees responded to an advertisement on the internal network in the four municipal administrations. The announcement provided contact information of the course leaders and there was information about the course itself as well as about the research project. The main groups of employees were nurses, school-nurses, nursing assistants, teachers, consultants, and secretaries in the public services.
The final sample included 119 employees who were randomized into two CWS groups. Shortly after the randomization, the intervention in the first CWS group started, and after six months the intervention in the delayed CWS group started. The delayed intervention group functioned as a control group during the first six months. Additional data collections were carried out on four occasions in both groups during four years after the interventions.
Linear mixed modelling was used for analysing intervention effects (articles 1 and 2). Structural equation modelling (cross-lagged analysis) was used for the analysis of prospective associations between social support, generalized self-efficacy and depression (article 3).The CWS course seems to have succeeded in reducing symptoms of depression, and the effect was maintained during the four-year follow-up period, although weakening slightly, towards the end (paper 1). The CWS course appears to increase generalized self-efficacy, self-esteem and vitality among participants and the effects are maintained over a period of four years, however, again weakening slightly towards the end (paper 2). Results presented in the third article show that self-efficacy and social support predicted change in symptoms of depression prospectively (paper 3).
In the bigger picture, the three papers in this thesis may contribute to more effective workplace interventions for the promotion of mental health and prevention of mental ill-health, and also contribute to more interest in research on effects of workplace interventions. Since there are presently few evidence-based interventions available for the promotion of mental health in workplaces, more studies which can throw light on the efficacy and effectiveness of such interventions are needed. Also, more research on the interrelatedness of factors of importance for positive mental health in workplaces is needed. Employees will most likely always experience some degree of stress and uncertainty. The focus on psychological resources and mastery may prove to be an important approach.