Absenteeism and stress-related depression
Ms Prone has (perhaps inadvertently) underscored the stigma associated with the absenteeism of which she writes by using the generally accepted term for the condition as “stress”.
Bearing in mind some levels of stress are not only acceptable in life generally but in many instances are beneficial to ensuring positive outcomes, it seems to me the issue that leads to lengthy absences from work, and the appointment of people to “acting” positions is, in fact, stress-related depression.