Q. "What should we tell the staff about an employee’s absence while on leave?"
Answer:
Federal law requires that you keep confidential any medical information you obtain. You should tell your staff only that the employee is out on leave.
The employee’s direct manager (or whoever does the scheduling) may need to know the expected duration of the leave, but very few, if any, managers or staff will need to know why the employee is on leave.
Reasons for extended absences may become sources of gossip, so minimizing who knows the reason for the leave lowers the risk of those details becoming public. If anyone comes to you with questions, you can remind them that for the sake of everyone’s privacy, you don’t discuss any employee’s personal matters (and neither should they).