He just seems to be acting strangely. Talking to himself a lot and just seems uncomfortable and panicking more. He is spending more time in his room. He normally gets A*/A in his tests (he's doing A-Levels) but a few times the past year he has just handled them terribly. Broke down and had to go home one time, and another just sat there and did nothing.
He's self-harmed in the past and had ditched some friendship groups before quite randomly although this was a few years ago now.
I just don't know if this is normal for 18-year old or not.