Pubdate: Sat, 30 Nov 2013
Source: Denver Post (CO)
Copyright: 2013 The Denver Post Corp
Contact:  http://www.denverpost.com/
Details: http://www.mapinc.org/media/122
Author: Electa Draper

MULTIPLE NAMES, ONE KEY INGREDIENT AND BROAD EFFECTS

There are hundreds of strains of marijuana - each containing hundreds 
of different chemicals - but only one molecule makes much difference, 
scientists say.

It's all about the THC.

Purveyors and boosters of marijuana - or cannabis - whether 
recreational or medicinal, counterclaim that the experience varies to 
great effect among all the amazing varieties cultivated over 
thousands of years.

Almost five millennia after the Chinese used medicinal cannabis, 
Colorado voters approved it in 2000, and they did the same for adult 
recreational use in 2012. A majority of the state's voters have 
decreed cannabis is good medicine and good fun, but they might not 
know what the drug is doing to the body.

When a person smokes, inhales or ingests marijuana or pot - the 
green, brown or grayish dried and shredded leaves, stems, flowering 
buds or seeds of plants called cannabis sativa or cannabis indica - 
more than 200 different chemical compounds course through the body. 
About 60 of them are called cannabinoids.

"Everybody likes something different," said Ean Seeb, co-owner of the 
Denver Relief Medical Marijuana Dispensary. "They can now pick what 
really works for them."

Yet after some 75 years of scientific research, it has been found the 
concentration of the psychoactive compound, THC, is what really 
matters, said psychopharmacologist Kari Franson, an associate dean 
and professor with the University of Colorado Skaggs School of 
Pharmacy and Pharmaceutical Sciences.

Franson worked at an institute that studied the effects of 
cannabinoids in healthy volunteers in the Netherlands, where it was 
easier to do research on it than in the U.S.

"You can study, study, study it, but it's THC 
(Delta-9-tetrahydrocannabinol) - that is the active ingredient," 
Franson said. "And there are certain things that happen to everyone 
who takes THC."

These, she said, are a feeling of pleasure or high, motor 
instability, decreased reaction time, attention deficit and increased 
heart rate.

"People think it mellows them out, but it causes an average increase 
in heart rate of 16 beats per minute," Franson said. "That's why 
people who take high doses they are unaccustomed to can experience 
significant anxiety or paranoia."

Other THC effects commonly experienced are increased appetite, 
decreased nausea, decreased motivation and decreased pain perception.

Additional typical effects are bloodshot eyes, decreased pressure 
inside the eye (it's used to treat glaucoma), heightened sensory 
perception (intense colors and sounds), distorted sense of time and 
sometimes a dry mouth.

Some effects are felt as soon as THC enters the bloodstream - much 
more quickly if inhaled. Delivery is key - joint, blunt, water pipe 
or a volcano (in which vapor only is collected in an expandable bag). 
Effects typically last an hour to a few hours, but the fat-soluble 
chemicals stay in the body for much longer.

Absorption of ingested THC is much slower.

After the high is over, some users feel sleepy or depressed.

Whatever is happening, Franson said, it's THC that's doing it.

"I think it all has to do with dose. The rest is marketing," Franson 
said. "It's folklore."

Users beg to differ.

Different effects

Seeb and many others say the two main types of cannabis, sativa and 
indica, produce very different effects. Marijuana strains range from 
pure sativas to pure indicas, but most are combinations or hybrids 
after thousands of years of cropping and recropping, he said.

Indica, nicknamed "in da couch," provides a deep feeling of 
relaxation or sleepiness compared with sativa, "viva sativa," which 
provides a more energetic or uplifting high, Seeb said.

Other users have strong preferences for different tastes and smells, 
which contribute to the subjective experience of pleasure.

"There are really pronounced differences across thousands of 
strains," Seeb said. "Some smell very sweet, like oranges or grape 
Kool-Aid. Some people like the stinkiest cannabis they can find. It 
can smell like skunk, diesel fuel (Bio-Diesel) or a dirty diaper 
(Sour Diesel). Gumbo is a delicious, sweet and spicy indica strain 
with beautiful floral hints, but also strong and pungent."

Seeb, who suffered a traumatic skiing accident that left him with 
chronic muscle spasms in one arm, said he is a big fan of Ultimate 
'91 ChemDawg. It helps him relax his muscles and fall asleep after 
long workdays of 16 to 18 hours. No motivation problems here.

"I can't make any claim one strain will have any one effect on 
everybody," Seeb said. "What makes one person giggle will make 
someone else paranoid."

Secondhand smoke

For those who abstain and wonder about whether making their way 
through a haze of marijuana smoke can get them high, Franson says not to worry.

"It takes an absurd amount of marijuana secondhand smoke to cause a 
positive test in a nonsmoker," Franson said.

A test 20 years ago showed that it required the smoke of 14 marijuana 
cigarettes in an unventilated 10-foot-square room before a nonsmoker 
had detectable amounts in his system.

"That's pretty smoky," Franson said.

Most of THC's activity is in the brain and central nervous system, 
although there are receptors located in the heart and other cells, 
such as the body's inflammatory-response cells.

Human bodies naturally manufacture chemicals similar to THC, which is 
why it works on us, Franson said. It hijacks receptors in the brain 
used by natural chemicals called neurotransmitters, specifically 
endogenous cannabinoids. One of them, anandamide, has been identified 
as regulating mood, memory, appetite, pain, learning and understanding.

These receptors are all over the brain - including the basal ganglia 
(which affects involuntary muscle movements), the hippocampus (used 
in short-term memory) and the cerebellum (which controls motor coordination).

"The cannabinoid receptor system is one of the biggest systems. Your 
brain is chock-full of them," said Dr. Christian Hopfer, an associate 
professor of psychiatry at University of Colorado Hospital's Center 
for Dependency, Addiction and Recovery.

"You need (the body's natural cannabinoids), and it has an effect 
when you're messing with those receptors," Hopfer said.

THC mimics the body's cannabinoids. Both interact with the same 
receptors. When THC binds to the receptor, it interferes with normal 
brain function, such as dopamine regulation.

Dopamine is part of the body's natural reward system and a key 
molecule in many brain functions, such as attentiveness, motivation, 
learning, memorization and motor control. THC increases dopamine in 
the short term, but ultimately interferes with the body's own reward circuit.

One of the body's own cannabinoids' purposes is to decrease the 
excitability of brain cells, or neurons, activated by adrenaline (or 
norepinephrine) in a fight-or-flight response to a perceived threat.

"But we eventually have to turn off this response or the neuron 
dies," Franson said.

That's the job of the body's cannabinoids. But they jump on and jump 
off receptors much faster than THC, Franson said. The body's 
cannabinoids don't create a high.

"But THC jumps on and stays there," she said. "It has a prolonged and 
pronounced effect."

Chronic consumption

With chronic cannabis consumption, the body decreases the number of 
receptors for its cannabinoids. Researchers have found that this 
results in reduced blood flow - and glucose and oxygen - to the 
brain. This could manifest as attention-deficit, memory loss and 
other impaired mental abilities.

"There is evidence you don't recover all your mental capacity when 
you quit using," said Hopfer, who treats marijuana and other 
addictions. "It's a very insidious addiction. It's very hard to 
treat. Its effects are subtle, gradual and less dramatic. And it's 
been trivialized."

He said he thinks the media overall has been pro-marijuana in its 
coverage of legalization.

"People shouldn't assume they know this drug based on Cheech and 
Chong movies," Franson said.

Marijuana continues to be listed by the U.S. Food and Drug 
Administration as a Schedule I drug - high potential for abuse and no 
currently accepted medical use - along with opiates and derivatives 
(heroin), stimulants (methamphetamine) and hallucinogenics (LSD) and 
depressants (methaqualone).

"There's something crazy about the feds labeling cannabis Schedule I 
and states legalizing it," Hopfer said. "It strikes me as a bad way 
of doing public policy. The truth is we don't really know that much 
about marijuana. We need to sort it out. But we have declared it a 
medicine by popular vote. It's a bad system. Now the popular view 
here is that it should be regulated like tobacco."

When cannabis is smoked like a cigarette, the smoker's lungs take in 
a horde of chemicals and particulates.

"Do I know that direct contact of these compounds doesn't harm the 
lungs. I don't know that. And nobody knows that," Franson said.

Cannabis boosters and detractors offer conflicting evidence of 
whether it prevents or causes cancer, or does both.

"We just don't have full understanding," Franson said. "I think we 
ought to know what this stuff does before we (broadly) use it as medicine."

Her main complaint about cannabis as medicine is that it's not 
"pharmacological," by which she means you can't administer a 
consistent dose and predict a consistent response.

Nevertheless, she acknowledges cannabis is being used successfully to 
alleviate pain, lessen the bad side effects of chemotherapy and 
prevent blindness from glaucoma.

And, with much less scientific evidence behind it, it is also used to 
treat epileptic seizures, stop the spread of cancer (with a chemical 
called cannibidiol, not THC), slow the progression of Alzheimer's 
disease and more. Franson said these claims are not well-supported.

Where cannabis is concerned, however, many voters and users are 
willing to rely on anecdotal evidence and personal experience - and 
are just trying it out as a cure for an increasing number of ailments.

"We have such a wide variety of patients who come," Seeb said. "We're 
really starting to see the plant is a miracle plant that heals many things."
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MAP posted-by: Jay Bergstrom