nglihua: Cool. What kind of project? Like, some sort of report? If so, can we have a look at it when you're done?
Corlist: Interesting reply, but I think those drugs you listed are more common with adults than the youth.
Here's some simple answers to your question that are more youth-orientated:
1) In my opinion, the most common drugs people first encounter are caffeine, nicotine, alcohol and cannabis. Caffeine is legal and available to anyone, so much so that people don't treat it like a drug. Nicotine and alcohol are both also readily available, since they're legal. The age restriction is only a minor hindrance. And finally, cannabis for a number of reasons: Firstly, it's everywhere - probably easier for people under 18 to buy than alcohol. Secondly, it's pretty cheap - ?10 pocket money is not going to fund a cocaine habit, but ?20 for 3g of weed is affordable. Finally, it's effects are quite minimal compared with other, harder drugs - maybe the extreme effects of cocaine, ecstasy or heroin would be too much.
2) There's a lot of evidence to suggest that getting intoxicated to alter your perception is completely natural. Almost as natural as eating, sleeping and sex. Check out the following New Scientist articles for some in-depth information:
You might not be able to access them, unless you've already paid for a subscription. Chances are though, you school probably has a subscription, so they can either get it for you, or let you access it via a proxy.
3) In terms of harm, the only damage worth talking about from those drugs would be from prolonged use in the young. There's evidence that taking drugs while the brain is developing can lead to impairment, but I've not got any sources I can give you. There's also the problem of addiction, which can lead to all sorts of issues. It's worth noting that cannabis is the least addictive of the four drugs I mentioned in the first place. Check out this
news article, in particular the graph of each drug's relative harm.
Hope that helped.
