1. MYTH: Marijuana is Harmless
TRUTH: Sure, it can’t directly kill you – but that doesn’t mean that pot is risk-free.
Regular marijuana use has been shown to be associated with long-term problems,
including poor academic performance, memory loss and lung cancer. To a developing
brain, like those of teenagers, marijuana can be especially toxic -- using pot can lead
to panic attacks, depression and other mental health problems, not to mention
increased anxiety.

2. MYTH: Marijuana is Not Addictive
TRUTH: But what you didn’t know is that more teens enter treatment each year with
marijuana as the main substance that they abused. In 2004, 64% of teens were
admitted for treatment for marijuana as their main drug of choice vs. 36% of all other
substances including alcohol. Marijuana is addictive, as it meets the criteria for
substance dependence established by the American Psychiatric Association including:
        Tolerance (needing more of the substance to achieve the same effects)
        Withdrawal symptoms, using a drug even in the presence of adverse effects
(you smoke even though bad things have happened when you do)
        Giving up social, occupational or recreational activities because of substance
use (you quit your sports team or job because they get in the way of your drug use.)
The desire for marijuana can have a powerful pull over a user – and can make it hard
to quit.

3. MYTH: Marijuana Isn’t As Bad As Cigarettes
TRUTH: Nope, sorry. Pot actually contains many of the same cancer-causing chemicals
found in tobacco. Puff for puff, smoking marijuana may increase the risk of cancer
more than smoking tobacco does.

Therefore, if you smoke pot regularly, you may experience the same breathing
problems as those who smoke cigarettes. To put it plainly, walking up flights of stairs
will seem difficult, and if you’re an athlete -- that unattractive wheezing and coughing
caused by excessive smoking won’t look so hot (or feel so good) on the playing fields.

4. MYTH: Driving While High is Safer than Driving Drunk
TRUTH: Hardly. In a study reported by the National Highway Traffic Safety
Administration, even a moderate dose of marijuana was shown to impair driving
performance, since it affects alertness, concentration, perception coordination and
reaction time – essential skills required for safe driving. Researchers also found that
17% (1 in 5) of crash victims under the age of 18 tested positive for marijuana.

5. MYTH: I Can Smoke Pot and Still Get Straight A’s
TRUTH: Hey, anything is possible – but there has been a lot of research done that
states the opposite. Researchers have found that heavy marijuana use may be
especially problematic during teens’ peak learning years, when the brain is still
developing, since smoking pot can impair your ability to concentrate and retain
information. This can cause poor academic performance. You might think you’re doing
well in school – but you’ll never know if smoking pot is inhibiting your true academic
potential.
Some Facts You Just Can’t Argue With:
        Smoking marijuana leads to some changes in the brain similar to those caused
by cocaine, heroin and alcohol.
        There is 50-70% more cancer causing material in marijuana smoke than in
cigarette smoke. Although it’s constantly promoted as “all natural,” marijuana smoke
contains more than 400 chemicals.
        THC (or tetrahydrocannabinol), the primary intoxicant in marijuana and hashish,
is rapidly absorbed by fatty tissues in various organs. Generally, traces (metabolites)
of THC can be detected by standard urine testing methods several days after a
smoking session. However, in chronic heavy users, traces can sometimes be
detected for weeks after they have stopped using marijuana.
        Long-term marijuana use can lead to addiction.
SOURCE: Unless otherwise specified: "Marijuana Myths &
Facts: The Truth Behind Popular Misperceptions." ONDCP and
NIDA
Five Myths About Marijuana