I will go one step further.
If someone has ADD and cannot focus for long enough periods of time to run a plot scene and associated paperwork that Wizzbang MUSH states are requirements for their plot staff, then they should not be allowed to be plotstaff if they fall behind on what they are signing up to do.
If someone enters into a major depressive episode, as I did before my last exit from mushing, and they cannot log in or participate in a manner that is expected of the position they've taken or the group they are trying to be part of--then they should withdraw from that position and inform their group that through no fault of that groups other members, they need to pull a l and take a break.
Etc. If your illness or life circumstance makes it so that you are incapable or minimally capable of doing things in a timely manner, or in a respectful manner because you are so up and down with your emotions...
Then yes. You should not disrespect the rest of the community by forcing others to deal with your problems that they can't really help with. You should not clutter a game and make everyone's time there less pleasant with your outbursts; nor assume that people who are not acting out don't have some serious stuff they are dealing with as well.
I do not think we should not expect in an interactive collaborative hobby some semblance of emotional and mental hygine. And honestly? People while they may be initially disappointed DO understand or respect that, if you are upfront and do not drag them unwilling or unwarned into your business.
Or if they don't, then that is valuable info to have for the future.