Thinking further on the dementor issue, and dementors in real life, personal or otherwise, I think there are cultural and political dementors.  Not that the individuals filling the dementor role have the general effect on everyone like in the Potter books, but on categories of people.  Think of celebrities or politicians that for whatever reason, you absolutely despise.  Sometimes the reasons are rational, sometimes not.

Anyway, this is probably stretching the notion of dementors too far, but I thought I’d add it to the discussion.