Pot a gateway drug? Are you kidding? Why do alot of drug addicts start out on pot? Do you really think it's a good idea to jump right into crack? Most people aren't THAT dumb. Let me just explain my opinion. I'm not a professional in ANY way, but nothing you can say will make me think any different.
When kids are experimenting at a young age, they are more prone to be doing it to go along with the crowd and fit in. Add to that possible problems at home that could be affecting the way a child grows emotionally, and could have negative effects on the self-esteem of the user. Now that person uses a drug which will probably make them feel better. The young person with the negative self-esteem will continue to use, and also to possibly move on to harder things that may or may not make them feel better. As a result, school may or may not suffer, usually it does, and all the extreme negative things that could possibly happen, likely will happen.
Those kids who do make it through HS by the grace of God, then may or may not go on to lead underproductive, meaningless lives, it is true that smoking marijuana makes you somewhat lazy, but if you are already prone to laziness, that is when it really has the effects. Those people who are hard workers, and know when and how to have their fun, can lead VERY successful lives.
I started smoking marijuana at 20, I experimented late, and I think that was a benefit because I have a high IQ (Dr.'s told me that, I'm not bragging), and I knew the side effects of being addicted to drugs, but I also am naturally curious, and I like to find things out by personal experience as well as 'book learnin', and so I moved beyond pot...and do you know what I realized? My self esteem was too high to even want to do those hard drugs. They had no appeal for me, as a matter of fact, I was able to realize the negative way the 'uppers' made me feel. So I stopped. Now I just smoke weed. Very often, and the only reason I think I'm gonna quit when I move in 3 months is because I don't like the negative effects smoking has on my lungs. Every situation is different, and I am sorry your son fell into the web of addiction, if you're worried about burying him at 22, then he must have started experimenting when he was young, and it was YOUR responsibility if he was a minor in your roof to make sure he didn't get caught up in the drug scene. And I am not trying to be insensitive to what this woman is going through (To those of you who are gonna jump on me for being a horrible person) because let me just say that had I started experimenting whern I was a teen, I'd probably be dead or in need of rehab right now. I just wasn't "cool" enough to hang with the people who did drugs when I was in school, and I thank God NOW that I was a loser in HS.