My friend just told me drove drunk “for fun”. Is this a cry for help, or is he just an idiot?

Here’s the story: I get a text from my friend tonight. He asked me if I ever felt the urge to drink and drive. I say “no, see a therapist” (laughing emoji). This guy has dark humor so I assume that he is not serious, plus he’s never done anything like this before and generally is a smart guy. Anyways, the conversation goes on for a bit and I say to him “I can’t tell if you’re serious, but don’t d&d.” He replies “too late I’m backing out”. I don’t believe him, so I say “send me a photo right now”, and he does. I ask him if he’s drunk. He says he is. I say “Are you fucking stupid. Go home. If you need something, I’ll drive you”, He leaves me on read. I call him, and he seems happy, which pissed me off. He explains that he “was hungry and wanted to see if he could handle it”. I cuss him out, told him to message me when he’s home, and hung up. He messages me about an hour ago, so he’s safe. I’m very pissed off at him right now, and he’s drunk, so I’m going to wait until things cool down for me to talk about this with him. If I saw him in person right now, I would swing at his face.

My personal emotions aside, I can’t tell if he’s just young and dumb (we’re both 21) or if he’s actually crying out for help. Out of our friend group, I’m the only one he told. He literally went out of his way to let me know what he was doing. I’m going to keep this between me and him, but I have absolutely no idea how to approach this. He’s never been the type to do something like this. That’s what’s throwing me off. It’s so out of character for him. He had no reason to do it, either. There wasn’t a party or anything. He just got drunk at his house and decided to drive.

I’m very serious about mental health (I’ve been through a lot myself) so I might just be assuming he’s crying for help because I used to do the same thing in my own way. But I also know there are people who do this because they are just inconsiderate, immature and believe they are invincible. They haven’t experienced the consequences of their actions before. I can’t tell which one my friend is.

Someone please chime in here. I feel like I might be overreacting, but I’m suddenly extremely concerned for my friend.