When teens see their friends using drugs and enjoying them, it makes them curious and think that they can do it without consequences. That is certainly not the case. What they might not see is that their friends could be suffering from side affects such as cancer and others.
A recent study showed that 47% of teens think that drugs are harmless because of T.V. and movies. It also showed that teens who see 3 or more "R" rated movies a month, are 6 times more likely to try drugs and other substances. First off, the characters in movies are only characters meaning the drugs the use are most likely just props. Also, the characters in movies who usually use drugs are adults. Drugs will most likely have a lesser effect.
Many unhappy and depressed teens will turn to drugs to solace them. These people don't have a proper outlet to vent frustration or a trusted confidant. Although many think the only way to make them feel better is through drugs, that is not the case. Exercise has been proven to release endorphin's which stimulate happiness and even a walk in the park could help a lot.
Teens who can’t tolerate being alone, have trouble keeping themselves occupied, or crave excitement are prime candidates for substance abuse. This might give them something to do, but there are many other ways to occupy yourself. This (objectively) is the worst reason to try drugs. No reason is good, but on a list of reasons you should never do drugs, this is the worst. There are many things to occupy your mind, instead of drugs. Exercise, reading, drawing, anything else would literally be better than doing drugs.
Some teens will use drugs just to prove peers or elders wrong. And, depending on their personality they will use different drugs. Methamphetamine, or meth, encourages aggressive, violent behavior, and can be far more dangerous and potent than alcohol. Marijuana, on the other hand, often seems to reduce aggression and is more of an avoidance drug. An easy way to avoid this is to just talk to the teens about their problems and reach an understanding.