I'm currently dating someone who suffers from depression and anxiety and he does something super weird and I'm wondering if it's a symptom of depression or something else :

He has two very different ways of speaking and texting. One is friendly, laid back and seems very natural. He will use some slang, abreviations and emojis while texting. The other one is extremely polite, proper and almost feels academic and robotic. He will use the complete words while texting, use old fashioned and weird, but very grammaticaly correct, sentences. And never ever any emojis in texting.

I would say one feels like how you're talking to a close friends and the other one is how you would talk to the chairman of a big university. Wich I am not.

Not sure if I should bring it up or not ?