Objectives Major depressive disorder (MDD) is associated with absenteeism. In this study, the effectiveness of collaborative care, with a focus on return to work (RTW), was evaluated in its effect on depressive symptoms and the duration until RTW in sick-listed workers with MDD in the occupational health setting.

Methods In this randomised controlled trial, 126 sick-listed workers with MDD were randomised to usual care (N=61) or collaborative care (N=65). Collaborative care was applied by the occupational physician care manager, supported by a web-based tracking system and a consultant psychiatrist. Primary outcome measure was time to response. Secondary outcome measures were time to remission, depressive symptoms as continuous measure and the duration until full RTW.

Results Collaborative care participants had a shorter time to response, with a difference of 2.8 months. However, no difference was found on time to remission or depressive symptoms as continuous measure. With a mean of 190 days in the collaborative care group, and 210 days in the usual care group, the groups did not differ significantly from each other in the duration until full RTW. Adherence to the collaborative care intervention was low.

Conclusions These results do not justify a widespread implementation of collaborative care in occupational healthcare, as it was operationalised in this study. However, since the study might have been underpowered for RTW and because treatment integrity was low, further research, with larger sample sizes, is needed to develop the best fitting (collaborative care) model for addressing RTW in depressed sick-listed workers.

Trial registration: ISRCTN78462860