Should you try and find out what happened to a friend that just disappeared one day?

I am 20F at uni in the UK. There was this guy on another course at the same uni that I saw quite regularly last term. He used to message a lot in our friends' group chat and even though he was really busy as a med student, I was still used to socialising with him about once a week. No one's heard anything from him since New Year's Day. He's stopped posting on social media. I sent him a checking-up message on Instagram about a month ago which he hasn't even seen, and a HBD chat on Snapchat about ten days ago which he hasn't even opened. He honestly used to message a lot so this is really weird. The other reason I'm worried is he told me he had drinking problems - sometimes he went to football games and would black out and not be able to remember how he got home, or if he had nothing to do in a day, he might just binge-drink by himself at his house. Usually, when someone disengages like this, it's probably mental health/low self-esteem. Like I said, it's been over a month. Should I just leave him to it? Or should I try harder to find out what happened to him? If so, what could I actually do?