Pubdate: Fri, 03 Jan 2014
Source: Washington Post (DC)
Section: page A3
Copyright: 2014 The Washington Post Company
Contact: http://mapinc.org/url/mUgeOPdZ
Website: http://www.washingtonpost.com/
Details: http://www.mapinc.org/media/491
Authors: Brady Dennis and Ariana Eunjung Cha

MARIJUANA: KEY QUESTIONS ANSWERED

Some Basic Information About Pot and Its Effects As Legalization
Advances

On Wednesday, Colorado became the first state to allow legal sales of
marijuana for recreational use. Washington state will do the same this
year, and other states might follow suit. Here are answers to some
basic questions about marijuana, its effects on the body and the
issues raised by legalization:

Q: How does marijuana work?

A: Marijuana's main active ingredient is delta-9-tetrahydrocannabinol,
or THC, found in the leaves, stems, seeds and especially the flowers
of the cannabis plant. It binds to the surface of nerve cells in
high-density areas of the brain involved in memory, thinking,
concentration, feelings of pleasure, coordination and movement, and
sensory and time perception. THC stimulates this communication
network, resulting in a marijuana "high."

Q: What are its medicinal uses?

A: About 20 states and the District allow the use of marijuana for
medical purposes. Most patients seek the drug for controlling pain
from medical conditions including cancer, nervous system diseases,
glaucoma and migraine. It is also being used to treat nausea and
improve appetites of people with HIV or chronic illnesses.

Q: What's the difference between smoking marijuana and consuming it in
food, powders or liquid extracts?

A: When marijuana is smoked, THC moves almost immediately from the
lungs to the bloodstream and to the brain. The effects can last one to
three hours. If it's eaten, say in brownies or cookies, it can take 30
minutes to an hour to have an effect, but the high can last up to four
hours.

Q: What are the health effects of marijuana use?

A: In the short term, it can lead to a rapid heart rate, increased
blood pressure, red eyes, dry mouth, increased appetite and slowed
reaction time. Long-term use has been linked to impaired thinking,
memory problems, panic attacks and other psychological issues. There
have also been studies showing a weakened immune system and, for those
who smoke the drug, impaired lung function.

Q: How much marijuana is safe to use? Can you overdose?

A: There is no recorded case of someone dying from an overdose of
marijuana, but it has been a factor in accidents or medical issues
that can lead to death.

The concentration of THC in seized samples of illegal marijuana has
been increasing over the past 30 years, with the average potency more
than doubling since 1998, leading to concern about the consequences
for young users. But scientists don't know much about the effects of
higher concentrations on the body and brain.

Q: Is it addictive?

A: It can be. Long-term use, especially by those who start at a young
age, has been shown to lead to addiction, with an estimated one out of
11 people who use it becoming dependent on it. Marijuana was
responsible for 4.5 million of the 7.1 million Americans dependent on
or abusing illicit drugs, according to the 2010 National Survey on
Drug Use and Health published by the Department of Health and Human
Services. Withdrawal symptoms are similar to those of withdrawal from
smoking and include irritability, sleep difficulties and anxiety.

Q: How does marijuana use affect the young?

A: Last year, Canadian and American researchers reviewed more than 120
studies examining cannabis and its effects on the teenage brain. They
found strong indications that early marijuana use can alter
development and contribute to mental health problems later in life.

"When you smoke marijuana, you cannot memorize or learn as you
should," Nora D. Volkow, director of the National Institute on Drug
Abuse, said recently on NPR's "The Diane Rehm Show."

"The other issue is that, the younger you start smoking marijuana, the
higher the risk not only to becoming addicted to marijuana, but it
also appears to increase the risk for addiction of other drugs in adulthood."

Volkow added: "What we know about the marijuana, as well as other
drugs, is that the effects of drugs in the human brain are not the
same when you take them as a child, adolescent or as an adult, and
this is because there are significant changes in the brain as we go in
the transition from childhood into adulthood."

Q: How does marijuana use affect driving?

A: One of the key questions Colorado lawmakers had to wrestle with in
setting up a legal marijuana market: When is someone too stoned to
drive? The answer isn't simple.

Prosecutors and some state lawmakers have long sought strict
blood-level limits for THC. Many marijuana advocates argue that the
drug affects people differently and that setting a hard limit could
lead to wrongful DUI convictions. They also argue that, unlike with
alcohol, traces of the drug remain in the bloodstream long after an
individual has smoked pot. Officials in favor of blood-level limits
say tests can pinpoint "active" THC in the bloodstream in the hours
immediately after marijuana usage.

Studies have shown that smoking marijuana tends to affect spatial
perceptions. Drivers might swerve or follow other cars too closely.
They can lose concentration and have slower reaction times. Such
findings have led some researchers to conclude that driving while high
greatly increases the chances for an accident, and that smoking pot
and drinking before driving is a particularly dangerous mix.

Every state forbids driving under the influence. But convictions in
drugged-driving cases generally rely on the observations and testimony
of police officers rather than blood tests. The White House, in a drug
policy paper last year, called on states to adopt blood-limit laws in
an effort to reduce drugged driving, but states continue to take
different approaches.

Last year, Colorado lawmakers approved a bill that creates a
"permissive inference" that someone with a certain level of THC in
their blood is impaired. Drivers suspected of driving while high
generally would have to consent to have their blood drawn, and they
could lose their license if they refuse.

Q: Should you use marijuana if you're pregnant?

A: A number of studies have shown that babies born to some women who
regularly used marijuana had an increased risk of cognitive and
attention deficits, memory and learning problems, low birth weight,
pre-term delivery and other issues. But more research is needed to
figure out to what extent environmental factors played a role in these
studies.  
- ---
MAP posted-by: Jo-D