I'll explain further, he's been doing weed on and off around September. Around November, he has constantly been smoking literally every waking hour of the day. It stinks up the house and no matter how much we air out the house, when we invite our friends over, they can smell it. The landlord's agent really isn't happy either, as currently, work is being done on the entire house. At first, none of us really were bothered, until he decided to continuously invite his friends over until 2am blasting music (literally until we knock on his door to tell them to leave).
There has been moments where we've knocked on his door and there wouldn't be an answer, attempt to sleep through everything and wait until the next morning to him saying, "Sorry, I was tripping. Couldn't hear you". We thought it was occasionally that he was taking LSD, but it's every couple of days when his weed high isn't strong enough for him.
Honestly, he's smoked so much in a short amount of time, that he has built an immunity to the "high" feeling of weed and he would stop smoking for like a day and get withdrawals and takes his anger out on everyone. The problem is, yes I've known him for ages and what he does in his spare time is his problem. We've all tried to talk to him, but he just doesn't get the message.
Mushrooms are another thing he's doing and he has started growing in his room... He's even said that he was planning on selling them to a dealer.