10:00 AM PT -- Ariana's ex, Pete Davidson, has jumped into the conversation, saying ... "Bravo Kanye West for standing up for yourself and speaking out against mental health. I can't explain to you enough how difficult and scary it is to be honest about stuff like this."

He adds ... "We need people like Kanye. No one should ever point fingers at you for your bravery in speaking about mental health. I'm seriously disgusted."

Before Pete posted his message, Ariana tweeted ... "last thing. stop weaponizing mental health. everyone."

Damn.

9:15 AM PT -- Ariana's replied to Kanye on Twitter, saying ... "with all due respect, i don't need to use anyone to promote anything. period." She adds it was just a joke comparing men and women, but did apologize for being insensitive and sent her well wishes to him.

Some fans were quick to say Ariana needs to retract her apology since she didn't owe him one ... to which she replied, "potentially triggering him? nah regardless of how i feel about a situation, i can also care about their mental health."

Kanye West is jumping all over Ariana Grande for making fun of his war with Drake and adversely affecting his mental illness.

Ariana did indeed make fun of the Kanye and Drake feud Friday, minimizing what Kanye says was a physical threat by Drake to him and his family. Ariana joked about "grown men arguing online," grousing it was taking attention away from her new single.

Ye fired back that he knew Ariana "said this to be cool and didn't mean no harm," but he still felt it was shading him. Fair point.

He goes on to say, "All of this foolishness weighed on my mental health so @arianagrande ..." In another post, he says, "No one would ever choose to end up in a mental hospital and diagnosed with a mental disorder but god chose me to publicly go through this journey and it is beautiful."

If we dare to interpret ... Kanye seems to be saying Ariana -- for whom he says he has love -- knows full well he's bipolar yet she jumped into the fray for pure self-promotion and in the process upset him.

It's interesting ... Kanye never called out Miley Cyrus. Ariana not only tweeted the guy fight was a distraction for the release of her single, but it also did the same for Miley. And, Miley was quick to respond by also making light of Kanye's fight with Drake. Yet Ye was silent on Miley.

We got Kanye in New York City Friday and asked him about the nature of the threat Drake leveled against him and his fam, but he was mum. We tried finding out from various Kim and Kanye sources all day long exactly what Drake said, but everyone is locked up tight as a drum.