Background: Long-term stress-related sick leave constitutes a serious health threat and an economic burden on both the single worker and the society. Effective interventions for the rehabilitation and facilitation of return to work are needed.

Objective: The aim of the study was to examine the effects of Guided Imagery and Music (GIM), a psychotherapy intervention including relaxation, music listening, and imagery, on biopsychosocial measures of work-related stress.

Methods: Twenty Danish workers on sick leave were randomized to music therapy versus wait-list control. Data collection was carried out at an occupational health ward in the period 2008-2010. Changes in salivary cortisol, testosterone, and melatonin were explored, and self-reported data on psychological stress symptoms (perceived stress, mood disturbance, sleep quality, physical distress symptoms, work readiness, well-being, anxiety, depression, immediate stress) were collected. Data regarding sick leave situation and job return were collected from participants throughout the study.

Results: Significant beneficial effects of GIM compared to wait-list after nine weeks with large effect sizes were found in well-being, mood disturbance, and physical distress, and in cortisol concentrations with a medium effect size. A comparison between early and late intervention as related to the onset of sick leave showed faster job return and significantly improved perceived stress, well-being, mood disturbance, depression, anxiety, and physical distress symptoms in favor of early intervention. In the whole sample, 83% of the participants had returned to work at nine weeks' follow-up.

Conclusions: The results indicate that GIM is a promising treatment for work-related chronic stress, and further studies are recommended.