Teen Gothic

I'm a bit confused on where the line between what is goth and what is shoegaze is. Mostly because I listen to Slowdive and Autumn's Grey Solace and they seem like they're basically the same stylisticly. But Slowdive has been pretty much strictly excluded from the goth label while AGS has been accepted by many I've talked with as goth. Idk, I don't really see strict categories very well. Just curious what others say about this.