Drugs & Clinical Trials

Clearing the Haze – Is Marijuana Addictive?

May 19, 2009 | By Dirk Hanson, MA | Share / Save / Email / Bookmark | 16 Comments

Drugs and Clinical Trials Category In the past few years, as addiction researchers have been mapping out the chemical alterations in the brain caused by alcohol, nicotine, methamphetamine, and other drugs, America’s most popular illegal drug has remained largely a scientific mystery. It is a drug that millions of Americans have been using regularly for years, and, from a clinical perspective, it remains the least studied illicit drug of all.

The most popular, and the least studied — not a prescription for rational decision making from a public health point of view. A variety of influences combined to force marijuana research off the table years ago, but the birth of “receptorology,” as molecular scientist Candace Pert once called it, and a more relaxed grip on federal funding has refueled the research.

Marijuana plant Why did cannabis research lag behind that of other drugs of abuse? For decades, the prevailing belief among users and clinical researchers alike was that marijuana did not produce dependency and therefore could not produce major withdrawal symptoms. Nonetheless, heavy marijuana users were claiming that tolerance does build. And when they withdraw from use, many report strong cravings. Marijuana withdrawal, which typically affects only heavy smokers, has not been well characterized by the research community.

Back in the fall of 1988, pharmacology professor Allyn Howlett and her colleagues at St. Louis University Medical School came up with strong evidence for the specific brain receptor to which the THC molecules were binding. However, the nature of the organic chemical itself — the compound in the brain that was meant to bind to those reported sites — remained unidentified until 1992. That year, William A. Devane, one of the researchers at Hebrew University in Jerusalem, along with Rafael Mechoulam and others, identified the body’s own form of THC in pulverized pig brains. The substance that stuck to the THC receptors was known as arachidonyl ethanolamide. Devane christened the substance “anandamide,” after the Sanskrit ananda, or bliss. It was left for animal physiologist Gary Weesner of the U.S. Department of Agriculture (USDA) to ask the burning question: “How do pigs use their anandamide?” In a study of the possibility of using anandamide as a safe sedative for animals, Dr. Weesner discovered that pigs treated with anandamide tended to show lower body temperature, slower respiration, and less movement — all indicators of a calmer porcine state of mind.

THC and its organic cousin make an impressive triple play in the brain: They effect movement through receptors in the basal ganglia, they alter sensory perception through receptors in the cerebral cortex, and they impact memory by means of receptors in the hippocampus. However, there has been little evidence in animal models for tolerance and withdrawal, the classic determinants of addiction. To the early researchers, it did not look like cannabis should be addictive. And for at least four decades, million of Americans have used marijuana without clear evidence of a withdrawal syndrome.

Nevertheless, some people appear to exhibit a classic pattern of dependency. By the year 2000, more than 100,000 Americans a year were seeking treatment for marijuana dependency, by some estimates. Marijuana Anonymous, an organization modeled on the principles of Alcoholics Anonymous, had become a robust recovery organization. What was going on?

Some of the mystery of marijuana’s effects was resolved after researchers demonstrated that marijuana definitely increased dopamine activity in the limbic area of the brain, as do all other addictive drugs. Tanda, Pontieri, and Di Chiara demonstrated that dopamine levels in the nucleus accumbens doubled when rats received an infusion of THC. It appears that marijuana also raises dopamine and serotonin levels through the intermediary activation of opiate and GABA receptors.

In 2004, a study group at the University of Vermont undertook a critical review of all major relevant studies of marijuana withdrawal. The meta-review appeared to bear out the theory that there are heavy marijuana users who suffer a verifiable and often vivid set of withdrawal symptoms when they try to quit. The most common clinically significant symptoms of abrupt withdrawal in heavy pot smokers, according to the research group, were

anxiety, decreased appetite/weight loss, irritability, restlessness, sleep problems, and strange dreams. These symptoms were associated with abstinence in at least 70% of the studies in which they were measured. Other clinically important symptoms such as anger/aggression, physical discomfort (usually stomach related) depressed mood, increased craving for marijuana, and increased sweating and shakiness occurred less consistently.

These are not trivial issues. As one long-time heavy cannabis user put it: “It’s not suicidal ideation but it’s the feeling that life will just never ‘be right’… when you suffer from symptoms that you’ve been told don’t exist, you are left looking for the wrong cause. So, if you’re told that marijuana withdrawal does not increase anxiety, anger, or ‘hopelessness,’ you want to look for a cause of those things… I went through withdrawal periods where I was inappropriately angry at the wrong thing, thinking that specific people were upsetting me when they were not.”

In the final post of this series, we will hear from more heavy marijuana users, in their own words. Personal observations and selected case histories of frequent marijuana users were gathered from anonymous, unedited comments posted on a blog site maintained by the author.

References

Hanson D. “Marijuana Withdrawal: A Survey of Symptoms.” In The Praeger International Collection on Addictions. Ed. by Angela Browne-Miller. Westport, Connecticut: Praeger, 2009. Vol. 2 pp.111-124.

Budney, A. (2004). Review of the Validity and Significance of Cannabis Withdrawal Syndrome American Journal of Psychiatry, 161 (11), 1967-1977 DOI: 10.1176/appi.ajp.161.11.1967

Kouri, E., & Pope, H. (2000). Abstinence symptoms during withdrawal from chronic marijuana use. Experimental and Clinical Psychopharmacology, 8 (4), 483-492 DOI: 10.1037/1064-1297.8.4.483

Rodriguez de Fonseca, F. (1997). Activation of Corticotropin-Releasing Factor in the Limbic System During Cannabinoid Withdrawal Science, 276 (5321), 2050-2054 DOI: 10.1126/science.276.5321.2050

Tanda, G. (1997). Cannabinoid and Heroin Activation of Mesolimbic Dopamine Transmission by a Common µ1 Opioid Receptor Mechanism Science, 276 (5321), 2048-2050 DOI: 10.1126/science.276.5321.2048

Tags: addiction, anandamide, cannabis, dopamine, drug addiction, marijuana, marijuana withdrawal, THC

16 Comments/Trackbacks

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AB390
May 19, 2009 | Permalink

If you live in California and favor legalizing marijuana, YOU can make it happen. Tell your representatives to support California Assembly Bill 390. It’s easy. Visit yes390.org

Eric
May 19, 2009 | Permalink

Thank you! For one, I am all for the legalization of drugs. With that said, I get upset when people say “marijuana is not addictive.” It is addictive, just like fast food, exercise, sex, etc… However, marijuana addiction is different than fast food, exercise, sex, etc… because you don’t have to work for the high, unlike the others (yes, even with fast food you have to get into your car and drive to McDonalds). People get use to the “easy” high, and thus depend on marijuana to give them that.

Anne
May 19, 2009 | Permalink

It would be nice if all drugs get out of the criminal scene. I think that is only effective if it happens all over the world at the same time. Otherwise it just attracts organized crime – like in the Netherlands …
Having said that, I have seen some pretty damaged brains after use of marijuana (in a scan).
Also, the marijuana from 30 years ago is not the same as is available now – it is now so much stronger …
I personally prefer meditation …

Marijuana Addiction Forum Admin
May 22, 2009 | Permalink

I run a forum for people who feel they are addicted to marijuana, I hear from people everyday who describe the symptoms listed above when they try to quit. It may not as be severe as the withdrawal from drugs like opiates, but a withdrawal can exist, particularly for heavy users.

samantha
May 23, 2009 | Permalink

I would be so interested to see the effects of marijuana withdrawal listed above compared side by side with effects of caffeine withdrawal, just to see things in perspective.

mahu
June 14, 2009 | Permalink

yes, as a hippy and way beyond ( if there is one) i was a pot user. My most long time friends considered me an addict although i could not ’see’ it. I started at 15 yrs old, and continued to this day if it were not for life imprisonment here in Philippines as i have no money for food, thus one starves to death in prison in Philippines, the country that most resembles USA in Constitutional Law and application.
After being forced into withdrawl, having smoked a single puff on a pipe of the narcotic at 10 PM or 47 yrs, then suddenly forced to stop i found my self irritable, angry, hungry, nervous, bouts of violence. This continued for 3 minutes, more or less, then i never thought about it again. Still, i will never forget the horrors of addiction to pot. I was an addict and this is a STAIN that even Jesus Christ can not disguise in those final days. I ruined my life by this one mistake. Yes, true i think, i have Severe ADHD and i was never given medications and one doctor suggested that i used pot as a ‘home made’ medication to calm my condition that i suffered from desparately all my life, left my family in shambles, distroyed our family, our reputation, put may people in prison, in the hosptial, even making me so called ‘wrong’ in my diagnosis of other illnesses in our family, as we could not afford a doctor so i was the eldest and acted as one, even wore the white coat…still, with all that… i could not med my own people.
maybe that was part of my pot addiction too, but someone had to become the family doctor…and i went to 10th grade, so why NOT ME? That is what they all said.
Anyway, without pot, the world would have few problems.

Charles M.
July 01, 2009 | Permalink

Hello, I am not at all opposed to the idea that marijuana can be addictive for some. However, I have to call into question the statistic reported in this article that over 100,000 Americans sought treatment for marijuana addiction in any year. I have a strong suspicion that this statement neglects to account for the number of court-ordered entrances in rehabilitation, which must be very high given that hundreds of thousands of Americans each year are charged with marijuana possession.

Anonymous
August 30, 2009 | Permalink

I think that people will become addicted to anything reguardless, for gods sake people get addicted to shopping and food if people are ‘addicted’ to marijahuana its because they have an addictive personality.

Nancy, Ojai
September 18, 2009 | Permalink

This article fails to mention that many of the so-called “withdrawl” symptoms share many characteristics of concommitant mental illnesses. Patients diagnosed with Bipolar disorder, cyclothymia, ADHD, ADD, and depression frequently display irritability, impulsivity, agitation, anxiety, stomach complaints, and changes in appetite when not on appropriate medication(s). We know many of these patients self-medicate with any number of mind-altering drugs. I think patients who suffer such symptoms when they stop smoking marijuana must be screened for mental illness(es) prior to assuming they are suffering from withdrawl.
Marijuana is NOT a narcotic (not even close). There are no health problems associated with its use. On the other hand, we know the destruction that a perfectly legal drug, alcohol, wreaks on our society.
What’s wrong with that picture?

Steven
October 01, 2009 | Permalink

Marijuana is so less harmful for the public than alcohol. They are both drugs/chemicals.

As a 20 year marijuana smoker there is no doubt there are withdrawal symptoms, anger was consistently one for me and it was predictable, when I would quit for a week or travel and go on vacation where I couldn’t bring my stash. And not just normal anger, for me it was rage for no valid reason, it was definately the pot withdrawal. Lethargy and sleepiness as well.

My questions is because there are withdrawal symptoms, does that automatically mean you are addicted. I quit 2 years ago, after smoking it all day everyday for the last 5 years prior to quitting. My family did an intervention and I went to rehab, but never have I had a craving since quitting, not during rehab or ANY time afterwords. But I’m supposed to not drink anything, because one addiction can become another, but am I addicted. Of course the experts say “if you question if you are addicted, that is just your addiction talking”. Though I just read on this side that recent studies have shown that a synthetic form of Kudzu vastly reduces cravings for alcohol. Subjects no longer desired to dram a vast amount. These are Harvard doctors. They say that alcoholism will be treatable like diabetes, where you avoid being hurt by it, but not necessarily cure it. Wow, but who knows, enough rambling for now….

maximillion swell
November 23, 2009 | Permalink

For the purpose of scientific/addiction discussion, this is a nice article. For the purpose of social/political discussion, compare heavy marijuana users with heavy alcohol users, then compare the outcomes.

Another interesting point, as stated above – “millions of marijuana users”, and 100,000 seeking help for addiction as of 2000. What is “as of 2000″ supposed to mean? What period does that cover? Last 20-30 years? Even if less than that 100,000 addicts (all non-lethal outcome), compared to millions and millions of users over several decades with no addiction symptoms sufficient to seek help? Reason to worry? I don’t think so.

miley
December 14, 2009 | Permalink

I think its fine to be addicted to marijuana. it doesnt have bad effect like alcohols do to our body. I am not addicted to marijuana, my brother does. And I really don;t care, as long as he can pay for it