Are you talking about crack or weed? If it's weed it can ultimately cause memory problems, and lung Cancer.

Weed does not have that harsh of effect on the brain. He may end up needing to take the hits at night, but he won't have much problems.

Ma'am, im my humble opinion, there is absolutely nothing wrong with smoking marijuana (and im not saying that because im what society calls a "pothead"), and I just want to say before I tell you why, that I am in no way trying to force my opinion on anyone, nor am I trying to endorse "weed" or try to make it sound cool. Marijuana as we all know is a plant that is grown in various parts of the world, and illegal nearly in all of them, because of the bullshit that society tries to cram down your throat everyday of the week because (for whatever reason) its just the popular thing to say marijuana is the devil. For me personally, I use marijuana on nearly a day to day basis, smoking before school, right after school, and usually around the time I go to bed. Now I realize that about 6 people probably just fell out of their chair when they read that, but honestly, Im a fully functional kid who made honor roll both quarters last semester, and I still have a part-time job and a band that I practice with at least once a week. Now I shared that little piece of my life to re-enforce the fact that, believe it or not, it is possible to use marijuana quite a bit and still be responsible. You just have to grow up and realize that you still have to get your shit done, but that doesn't mean that you cant have fun when you don't have anything to do. As far as the effects go, you say he only takes a few hits at night to chillaxe a little bit, hes really got nothing to worry about, he could do that every single night for the rest of his life, and get up the next day just as responsible and reliable as ever. I mean, anyone could, but there is a fine line you have to walk, theres a big difference in being a little pothead smoking "weed" about everyday, and just smoking yourself through the floor every hour of everyday. Which I think is stupid, and is the reason pot is illegal, people automatically think your going to smoke a few ounces a day until your completely stupid. And as far as the health risks are concerned, I wont go into extreme detail here, because I haven't got the time or the patience to type out every single flaw the common-folk has in their belief system about the health risks of Marijuana, a great place to check would be a site like Wikipedia, or some other non-government reference site, they should have all the information you could possibly want. The only main health risk that has ACTUALLY BEEN PROVEN IN MORE THAN ONE STUDY INVOLVING MANY DIFFERENT PEOPLE is lung cancer and brain damage, and both of them can be completely avoided, in fact upon legalization the risk of brain damage could be eliminated completely. As far as the lung cancer goes, as long has he isn't smoking joints, he should be good, because the tar in the paper can ultimately lead to lung complications. So get him a bong or a little pinch hitter and all is well. As far as the brain damage goes, it can easily be avoided. Most dealers who sell homegrown weed, will eagerly wait for months as their plant grows...however, once it comes time for harvesting, they are so sick of waiting that they decide there going to take the easy way out and instead of hanging their pot up to dry for a few days, they spray it down with pesticide and throw it in the microwave. Microwaving pot seriously depletes the THC..and thats where the pesticide comes into play. When you smoke weed that has been doused in pesticide it seems to intensify the high, but after you smoke it a few times you get used to it and it isn't as easy to detect pesticide in the weed...which will lead to potential brain damage if you toke on it too much (and even now im talking, years and years of ridiculous smoking) My point is, let him smoke, hes not hurting himself, going to turn into a bum, forget about his family, get his fist stuck in his mouth, or shrink to about 2 foot tall and looked smashed, regardless of what society wants to think The truth is the truth...and the truth will set you free Peace God Bless