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What Is It?

Marijuana is a mixture of the dried and shredded leaves, stems, seeds, and flowers of the hemp plant. The mixture can be green, brown, or gray. Hemp's scientific name is Cannabis sativa.

A bunch of leaves seems harmless, right? But think again. Marijuana has a chemical in it called tetrahydrocannabinol. Better known as THC. A lot of other chemicals are found in marijuana too-about 400 of them, some of which can cause lung cancer. But THC is the main active ingredient. [1]

What Are the Common Street Names?

There are more than 200 slang terms for marijuana from city to city and from neighborhood to neighborhood. Some common names are: pot, grass, herb, weed, Mary Jane, reefer, skunk, boom, gangster, kif, chronic, and ganja. [2]

How Is It Used?

Marijuana is used in many ways. Some users brew it as tea or mix it with food. Others smoke blunts-cigars hollowed out and filled with the drug. And sometimes marijuana is smoked through a water pipe called a bong. The most common method is smoking loose marijuana rolled into a cigarette called a joint or nail. [2]

How Many Teens Use Marijuana?

Ever heard that lame line "everybody's doing it?" Tell that person to check the facts. As part of a 2002 NIDA-funded study, researchers asked teens if they had used marijuana or hashish (another form of marijuana) in the past month. Of all the 8th graders surveyed, only 8.3% said yes; only 17.8% of 10th graders had used the drug in the past month; and just 21.5% of 12th graders. [3]

What Are the Common Effects?

Imagine this: You're in a ball game, playing out in left field. An easy fly ball comes your way, and you're psyched. When that ball lands in your glove your team will win, and you'll be a hero. But, you're a little off. The ball grazes your glove and hits dirt. So much for your dreams of glory.

Such loss of coordination can be caused by smoking marijuana. And that's just one of the many negative side effects. Under the influence of marijuana, you could forget your best friend's phone number, watch your grade point average drop like a stone, or get into a car accident. Even worse, high doses of marijuana use can cause anxiety and panic attacks.

Before we look at the damage marijuana can do, let's back up for a second and discuss a tricky truth. For some people, smoking marijuana makes them feel good. Within minutes of inhaling, a user begins to feel "high," or filled with pleasant sensations. A chemical in marijuana, THC, triggers brain cells to release the chemical dopamine. Dopamine creates good feelings-for a short time. [4]

Addiction

Here's the thing: Once dopamine starts flowing, a user feels the urge to smoke marijuana again, and then again, and then again. Repeated use could lead to addiction, and addiction is a brain disease.

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