My boyfriend smoked weed for years from about 15 up until he was 30, he's been clear of it now for over 5 years but I'm since I've known him (2 years) I've noticed he seems to suffer from symptoms of long term use (Eg paranoia and mood swings).
His paranoia is ridiculous, he'll overreact to situations and say they could have caused death (some may have but incredibly unlikely!) and he thinks of the worst outcome and doesn't accept any other answer (doesn't seem to be anxious about it though just states it will be really bad) and his mood swings are really bad, he'll blame me for tiny things (like him leaving his earpod on the table and me moving it then say that it could have broken etc).
I'm finding it really hard to live with at the moment and I've come to the conclusion he's either just like that naturally (paranoid and mood swings) or it's been brought on from the long term weed smoking.