Hello! I'd like to ask for some information about the verb to demotivate. I found it in some dictionaries, and a colleague of mine (a teacher of English, like me) insists on including this verb in the custom vocabularies for his Intermediate-level students. I, on the other hand, am doubtful because it seems to me that this word is a quite recent artificial derivative of 'demotivation', which is not that common itself, and thus isn't really a truly literary word. I may be wrong here.
Considering that using this word is acceptable, my other concern is prepositions. My colleague insists that demotivate as a verb can be used with preposition from, similarly to discourage from. I know that there are such expressions as 'to demotivate somebody', without preposition, but I haven't found a single example of using this verb with from.
I'd be happy to hear some expert opinion on this matter.