Pubdate: Wed, 22 May 2013
Source: East Bay Express (CA)
Column: Legalization Nation
Copyright: 2013 East Bay Express
Contact: http://posting.eastbayexpress.com/ebx/SubmitLetter/Page
Website: http://www.eastbayexpress.com/
Details: http://www.mapinc.org/media/1131
Author: David Downs

CAN POT HELP CURE PTSD?

New research suggests that the main ingredient in marijuana may help 
alleviate the symptoms of post-traumatic stress disorder.

It is believed that some 7.7 million Americans suffer from 
post-traumatic stress disorder, or PTSD. Yet current treatments for 
the sometimes devastating anxiety disorder have limited efficacy. 
Now, a Yale University professor, who recently made a presentation of 
his research at a conference in Oakland, contends that there is 
strong evidence that the main ingredient in marijuana, THC, not only 
helps alleviate symptoms of PTSD, but also may ultimately help cure it.

Yale associate professor of psychiatry R. Andrew Sewell has an 
impeccable resume: He's the former chief resident in neuropsychiatry 
at the University of Massachusetts School of Medicine, and his 
research is grounded in some pretty solid animal studies - which is 
the only reason why the United States government is permitting his 
multi-year lab test on about 120 people, specifically, veterans with 
intractable cases of PTSD.

PTSD can show up months or years after a person is exposed to trauma, 
and veterans are especially susceptible to it after experiencing the 
horrors of war. Symptoms include extended periods of flashbacks, 
agitation, and anxiety, which can be triggered by a thought, word, or 
object. It can lead to depression, insomnia, and abuse of alcohol and 
other drugs. Sewell sees PTSD regularly in his work with veterans at 
a Yale-affiliated center in West Haven, Connecticut.

But existing treatments for PTSD, including antidepressants like 
Prozac, Paxil, and Zoloft, have "limited efficacy," Sewell said, and 
side effects can include thoughts about suicide. "It helps a bit with 
emotional numbing, but it doesn't really do much for the other 
things," he said.

Sewell said the most effective cure for PTSD is "exposure therapy," 
which can be brutal. It involves revisiting the trauma over and over 
again until the memories of it are no longer overwhelming. Lots of 
veterans drop out of the twelve-week course at the National Center 
for PTSD during week three, when they have to write down what 
happened to them. "You have to be exposed to something that's very 
unpleasant that you've spent a lot of time and effort walling off in 
your own brain," he explained.

Sewell's theory is that the main active molecule in cannabis, THC, 
can speed up and enhance exposure therapy by increasing something 
called "extinction learning." Extinction learning is the process of 
learning new information that opposes the old. Sewell gave an example 
of what can happen to soldiers who return home after driving in Iraq. 
About 20 percent of Iraq war vets have PTSD.

"[In Iraq] you don't have to watch the road," he noted. "What you 
have to keep your eye on is little bits of garbage on the side of the 
road [because of improvised explosive devices] ... and also bridges 
are huge. ... Somebody can drop a frag grenade from the bridge and 
run off. ... Soldiers come back [to the United States]; they find 
they can't drive anymore because they're always crashing. ... They're 
scared of garbage. ... Bridges freak them out," he said.

After six months, most vets' symptoms go away on their own. New 
information overwrites the old. "These soldier reflexes never leave 
you completely, but they die away to the extent that you can live a 
normal life," he said. Except if you have PTSD, the reflexes don't 
die away. "Suppose some part of your reptile brain thinks if you walk 
under a bridge you're going to die," Sewell said. "Life becomes very hard."

Sewell said PTSD and other anxiety disorders might hinge on a defect 
in the extinction learning process in the brain at the cellular 
level. Our brain cells "talk" to each other using a chemical system, 
and the system's main switch is called the CB1 receptor. If you knock 
out the CB1 in mice or apes and subject them to shocks, they get PTSD 
and they're permanently shell-shocked. Conversely, stimulating the 
CB1 receptor enhances extinction learning in mammals. And guess what 
drug is really good at stimulating the CB1? Pot.

"It's not like they'd have to keep taking cannabis the rest of their 
life," Sewell said. "We're talking about a cure."

Here's the lab model: Sewell gets vets with PTSD and a control group, 
and then subjects all of them to electric shocks when they see a 
certain geometric pattern. They all learn to associate some squares 
with a zap. Then he takes away the shocks. Normal, healthy people in 
the control group quickly learn no more shocks are coming. They stop 
sweating and producing stress hormones. But PTSD sufferers are stuck. 
"They still respond to the shapes as though there will be a shock 
even when there is not a shock coming," he explained. "That's kind of 
what you see in the diseases of PTSD as well."

Sewell then gives each veteran about one milligram of pure THC 
intravenously ("Oh yeah they get high," he said) and sees if the 
vets' extinction learning re-starts. They should be able to learn no 
more shocks are coming and relax. Eventually, vaporized THC could be 
coupled with exposure therapy to treat PTSD, or other social anxiety disorders.

Sewell presented his ongoing study in Oakland on April 18 at the 
Multidisciplinary Association for Psychedelic Studies (MAPS) 
conference. MAPS scientist Dr. Sue Sisley called the approach 
"compelling." Thousands of vets are already using marijuana to manage 
symptoms of PTSD, she said, even as the federal government blocks 
research on the plant.

Marijuana science remains a political battlefield, Sewell agreed. "If 
you want to show cannabis is helpful for veterans and their sleeping, 
you're not going to get to," Sewell said. "If you want to show how .. 
it's a gateway drug, you name it, they'll throw money at you."

Update: A previous version of this story misstated the amount of THC 
Sewell have his study participants. It was one milligram, not one gram.
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MAP posted-by: Jay Bergstrom