It will depend on the problem presented by this colleague. If he complains, we can encourage him or emphasize the positive things or even just listen to him; but you can get overwhelmed very quickly. Often, people express their annoyance at the time they devote to listening, which is of no use.

One can then practice what is called benevolent sabotage ; it consists of listening to the colleague but pretending an emergency on something else so as to interrupt the crisis represented by the complaint at the moment it occurs and develops. And we invite this colleague to come back to us, but not on the subject of the complaint heard when the interruption took place.