Studies show that, when there is a leave of absence in the workplace due to mental disorder, this may trigger a chain reaction among the colleagues of the person on leave due to potential secondary stress. However, it remains unclear what experiences colleagues may have and how this chain reaction affects their mental health. The purpose of this research was to examine the experience of coworkers who were also affected when a colleague’s leave of absence was caused by a mental disorder, thus generating a chain reaction. We conducted a semi-structured interview and analyzed the data with Trajectory Equifinality Modeling (TEM). Our results revealed that colleagues carry the psychological burdens caused by the leave of absence and by the extra workload imposed by the co-worker’s absence. Management of such situations appropriately can prove challenging, which can lead to a chain reaction of mental disorders among co-workers. These findings indicate that early consideration of the colleagues is needed to prevent a chain reaction.