NIDA’s Dark View of Teen Marijuana Use

Federal study also discusses medical marijuana.

Considering the impasse on marijuana policy between state and federal governments in the U.S., the primary government agency in charge of drug research—NIDA, the National Institute on Drug Abuse—would seem to be caught between a rock and a hard place. Neuroscientists and other marijuana investigators who do research under NIDA grants have a fine line to walk in their efforts to disseminate research findings on cannabis.

From a public health point of view, NIDA is expected to keep up the pressure against drug legalization, or at least keep out of the fight, while also researching the medical pros and cons of cannabis. So it was with some interest that drug policy officials took in a recent article in the New England Journal of Medicine by NIDA director Nora Volkow titled “Adverse Health Effects of Marijuana Use.”

While the press has understandably centered on the risk of marijuana use among teens, which is the focus of the study, the report also contains some surprising admissions about marijuana’s health benefits as well as its addictive potential.

The teen risk emphasis comes from recent studies on two fronts—impaired driving and impaired brain function. The first is seriously confounded by dual use with alcohol, and the second is based, at least in part, on a controversial long-term study showing that marijuana use in the early years demonstrably lowers adult IQs.

No one would suggest that heavy marijuana smoking is good for developing teen brains, and there is sufficient evidence to worry about impairment to memory and to certain so-called “executive” cognitive functions. It is not clear how lasting these effects can be, but lead author Volkow is confident enough to say in a prepared statement that “Physicians in particular can play a role in conveying to families that early marijuana use can interfere with crucial social and developmental milestones and can impair cognitive development.” 

That these negative effects can be the outcome of heavy pot smoking in the teen years seems established beyond reasonable doubt. The extent and duration of these negative outcomes remain the topic of vociferous debate—although it is increasingly clear that the body’s endogenous cannabinoid system plays a key role in synapse formation during early brain development.

Meanwhile, the report re-emphasized the fact that marijuana is an addictive drug for some users—a fact that should not need re-emphasizing, but, lamentably, does. As Volkow and her co-authors write: “The evidence clearly indicates that long-term marijuana use can lead to addiction. Indeed, approximately 9% of those who experiment with marijuana will become addicted.”

Moreover, as regular readers of Addiction Inbox already know, “there is also recognition of a bona fide cannabis withdrawal syndrome (with symptoms that include irritability, sleeping difficulties, dysphoria, craving, and anxiety), which makes cessation difficult and contributes to relapse.” And, in line with the report’s overall theme, “those who begin in adolescence are approximately 2 to 4 times as likely to have symptoms of cannabis dependence within 2 years after first use.”

To their credit, the investigators decline to endorse the claim that marijuana use exacerbates or initiates episodes of illness in patients with schizophrenia and other psychoses, noting that “it is inherently difficult to establish causality in these types of studies because factors other than marijuana use may be directly associated with the risk of mental illness.” Furthermore, while early marijuana use is associated with an increased risk of dropping out of school, “reports of shared environmental factors that influence the risks of using cannabis at a young age and dropping out of school suggest that the relationship may be more complex…. The relationship between cannabis use by young people and psychosocial harm is likely to be multifaceted, which may explain the inconsistencies among studies.”

Indeed. The report also declares that the effects of long-term pot smoking on the risk of lung cancer are “unclear,” and that “the smoking of cigarettes containing both marijuana and tobacco products is a potential confounding factor with a prevalence that varies dramatically among countries.”

In conclusion, the strict demands of causality mean that the long-term effect of chronic marijuana exposure is not known with any certainty. It is possible, even likely, that these effects can vary dramatically from one smoker to another. But the equally persuasive demands of common sense dictate that inhaling dried, super-heated vegetable matter on a regular basis is likely to degrade your health, the more so if you are young and healthy to begin with.

As for other health issues: “The authoritative report by the Institute of Medicine, Marijuana and Medicine, acknowledges the potential benefits of smoking marijuana in stimulating appetite, particularly in patients with the acquired immunodeficiency syndrome (AIDS) and the related wasting syndrome, and in combating chemotherapy-induced nausea and vomiting, severe pain, and some forms of spasticity. The report also indicates that there is some evidence for the benefit of using marijuana to decrease intraocular pressure in the treatment of glaucoma.”

A detailed section titled “Clinical Conditions with Symptoms That May Be Relieved by Treatment with Marijuana or other Cannabinoids” brought additional research to light:

—Glaucoma: “More research is needed to establish whether molecules that modulate the endocannabinoid system may not only reduce intraocular pressure but also provide a neuroprotective benefit in patients with glaucoma.”

—Nausea: “THC is an effective antiemetic agent in patients undergoing chemotherapy, but patients often state that marijuana is more effective in suppressing nausea…. Paradoxically, increased vomiting (hyperemesis) has been reported with repeated marijuana use. [See various blog posts by Drugmonkey and me, starting with this and this.]

—AIDS-associated conditions: “Smoked or ingested cannabis improves appetite and leads to weight gain and improved mood and quality of life among patients with AIDS.”

—Chronic pain: “Studies have shown that cannabinoids acting through central CB1 receptors, and possibly peripheral CB1 and CB2 receptors, play important roles in… various models of pain. These findings are consistent with reports that marijuana may be effective in ameliorating neuropathic pain, even at very low levels of THC.”

—Inflammation: “Cannabinoids (e.g., THC and cannabidiol) have substantial anti-inflammatory effects…. Animal models have shown that cannabidiol is a promising candidate for the treatment of rheumatoid arthritis and for inflammatory diseases of the gastrointestinal tract (e.g., ulcerative colitis and Crohn’s disease).”

—Multiple sclerosis: “Nabiximols (Sativex, GW Pharmaceuticals), an oromucosal spray that delivers a mix of THC and cannabidiol, appears to be an effective treatment for neuropathic pain, disturbed sleep, and spasticity in patients with multiple sclerosis. Sativex… is currently being reviewed in phase 3 trials in the United States in order to gain approval from the Food and Drug Administration.”

—Epilepsy: In a recent small survey of parents who use marijuana with a high cannabidiol content to treat epileptic seizures in their children, 11% reported completed freedom from seizures…. Although such reports are promising, insufficient safety and efficacy data are available on the use of cannabis botanical for the treatment of epilepsy. However, there is increasing evidence of the role of cannabidiol as an antiepileptic agent in animal models.”

Volkow N.D., Baler R.D., Compton W.M. & Weiss S.R.B.  Adverse health effects of marijuana use., The New England journal of medicine,    PMID: 24897085

Grab Bag of Addiction Links

Recent reading from around the net.

Can Medical Marijuana and Recreational Marijuana Coexist?

“The Washington State Liquor Control Board released recommendations for what to do with the state's medical marijuana system now that recreational marijuana is legal.” [Atlantic Cities]

Premature claims of a cannabis addiction "cure"

“Have scientists found a ‘cure’ for marijuana addiction? New treatment blocks the kick that users get from the drug,” reports the Mail Online. Based on the evidence presented in the study, which involved animals, the answer to the Mail’s question is 'not yet'. [NHS Choices]

Can Gambling Machines Prevent Addiction?

“Today's digital slot machines and poker screens in casinos and at online gambling sites are capable of amassing a wealth of behavioral data on individual players, and they are on the verge of altering game play on the fly.” [Scientific American Mind]

Food for thought: UF researcher’s book lays out evidence for food addiction

“For some, the famous potato chip slogan “Betcha can't eat just one” isn’t a wager — it’s a promise.” [University of Florida Health]

New Zealand’s bold experiment with regulating recreational drugs

“It’s been nearly a century since the United States began its experiment in prohibiting recreational drugs besides alcohol, caffeine and tobacco — and virtually no one sees the trillion dollar policy as a success.” [Reuters]

More Than 1,000 Meet in Denver to Develop Drug War Exit Strategy

“Which state will be next to legalize marijuana? What do the Obama administration's recent announcements about marijuana legalization and mandatory minimums really mean?” [Huffington Post]

This Is Why Social Media and Drinking Alcohol Don't Mix (Infographic)

“Engaging with peers and customers on social platforms can be dangerous. Doing so while you’re under the influence of alcohol is downright irresponsible. “ [Entrepreneur]

Economists Predict Marijuana Legalization Will Produce "Public-Health Benefits"

“In their 2012 book Marijuana Legalization: What Everyone Needs to Know, Jonathan Caulkins and three other drug policy scholars identify the impact of repealing pot prohibition on alcohol consumption as the most important thing no one knows.” [Forbes]

Photo Credit: http://lifeonthebalcony.com/

Does Marijuana Withdrawal Matter?

What happens to some smokers when they cut out the cannabis.

People who say they are addicted to marijuana tend to exhibit a characteristic withdrawal profile. But is cannabis withdrawal, if it actually exists, significant enough to merit clinical attention? Does it lead to relapse, or continued use despite adverse circumstances? Should it be added to the list of addictive disorders in the rewrite of the Diagnostic and Statistical Manual of Mental Disorders (DSM) currently in progress?

Marijuana fits in fairly well with the existing criteria for clinical addiction—except for one common diagnostic marker. Among the identifying criteria currently used in the DSM, we find: “The presence of characteristic withdrawal symptoms or use of substance to alleviate withdrawal.” Opponents of marijuana’s inclusion as an addictive drug have long insisted that cannabis has no characteristic withdrawal symptoms, but this position has been severely eroded of late, as new research has consistently identified a withdrawal syndrome for marijuana, which includes drug cravings, despite decades of controversy over this basic medical question.

A group of researchers at the University of New South Wales, Australia, along with Dr. Alan J. Budney of the Geisel School of Medicine at Dartmouth, New Hampshire, writing in PLOS ONE, presented evidence that the characteristic withdrawal symptoms displayed by addiction pot smokers are in fact strong enough to be considered clinically significant.
(For more on the marijuana withdrawal profile, see HERE, and HERE. For a bibliography of relevant journal articles, go HERE).

But how does one go about determining if withdrawal reactions rise to the level of clinical significance? The researchers wanted to know whether functional impairment reported during abstinence was clinically significant, whether it correlated with severity of addiction, and whether it was predictive of relapse. 46 survey volunteers who were not seeking any formal treatment for marijuana addiction were recruited in Sydney, Australia. Users ranged in age from 18 to 57, with an average age of 30. After a one-week baseline phase, the participants underwent two weeks of monitored abstinence. Using a “Severity of Dependence Scale” (SDS) to measure variability in functional impairment, the researchers compared a high SDS subgroup to a low SDS subgroup in an effort to tease out whether functional impairments in high SDS participants were predictive of relapse. The researchers noted that earlier work had established that the symptoms most likely to cause impairment to normal daily functioning were: Trouble getting to sleep, angry outbursts, cravings, loss of appetite, feeling easily irritated, and nightmares or strange dreams.” The investigators broke these symptoms into two groups: “somatic” and “negative affect” variables.

The researchers then examined self-reports about the impact of cannabis withdrawal on normal daily activities.  While the common yardstick for withdrawal is typically taken to be intensity of cravings, the authors argue that this reliance on craving “may mask the extent to which symptoms led to functional impairment, as those who maintained abstinence may still have experienced clinically significant negative consequences from cannabis withdrawal (e.g. relationship or work problems resulting from the withdrawal syndrome.”)

As might have been expected, higher levels of cannabis dependence were associated with greater functional impairment. And while the average level of functional impairment caused by cannabis is “mild for most users, it appears comparable with tobacco withdrawal which is of well established clinical significance.”

And certain symptoms were, in fact, correlative: “Increased somatic withdrawal symptoms are predictive of relapse, and…. increased physical tension is a significant predictor of relapse.”

 Physical distress, a “somatic” variable, mattered more, in terms of relapse, than the amount of marijuana smoked, or any other symptom on the roster of functional impairments—including mood and other negative affect variables.

“In conclusion,” the investigators write, “cannabis withdrawal is clinically significant because it is associated with elevated functional impairment to normal daily activities, and the more severe the withdrawal is, the more severe the functional impairment is. Elevated functional impairment from a cluster of cannabis withdrawal symptoms is associated with relapse in more severely dependent users.”

Furthermore: “Targeting the withdrawal symptoms that contribute most to functional impairment during a quit attempt might be a useful treatment approach (e.g. stress management techniques to relieve physical tension and possible pharmacological interventions for alleviating the physical aspects of withdrawal such as loss of appetite and sleep dysregulation.)”

As with most studies, there are limitations. As noted, the participants were not in a formal cessation program. And while urine tests were used, there was no external corroboration of the self reports.

Allsop, D., Copeland, J., Norberg, M., Fu, S., Molnar, A., Lewis, J., & Budney, A. (2012). Quantifying the Clinical Significance of Cannabis Withdrawal PLoS ONE, 7 (9) DOI: 10.1371/journal.pone.0044864

Graphics Credit: http://www.addictionsearch.com/

Seeking a Patch or a Pill for Pot

Drug treatments for marijuana withdrawal.

Sometimes it’s easy to forget that marijuana is the most widely used illegal drug of all. We demonize it, yet we take it for granted. We punish citizens for its possession, but we call it a “soft” drug.

The idea of marijuana as an addictive drug--for some but by no means all users—still seems preposterous to a large number of recreational pot smokers. Yet these same people have far less trouble dealing with the existence of raging alcoholics surrounded by a majority of controlled, recreational drinkers or non-drinkers.

 For purposes of this post, we are going to stipulate that sufficient scientific evidence now exists to include marijuana in the category of addictive psychoactive drugs. Heavy, daily users of marijuana sometimes find themselves in an unexpected bind if they decide to quit cold. Perhaps as many as one or two in every ten heavy pot smokers will find themselves suffering from flu-like symptoms, loss of appetite, insomnia, vivid dreams, irritability, generalized anxiety, and other side effects that can be at least as unpleasant as quitting cold turkey after a long cigarette habit.

 Why didn’t we know this earlier? Perhaps for the same reasons that we didn’t know until the 1980s, as a general piece of knowledge, that cocaine was highly addictive. (Marijuana Anonymous didn’t start up until 1989). Doesn’t that sound absurd now, the state of our understanding of cocaine’s effects only 30 years ago? For people who suffer strong and repeatable withdrawal symptoms when they try to quit smoking weed, it is equally absurd to proclaim that what they are wrestling with does not resemble a genuine drug addiction (See the Addiction Inbox thread on marijuana withdrawal, which is now approaching 1,000 comments, and which constitutes a major database of self-reported data on marijuana withdrawal).

Having identified marijuana as classically addictive for a small slice of the user population, the focus has lately turned toward human laboratory studies, although most of the human studies thus far have been open-label trials rather than controlled double-blind studies. A group of researchers at Columbia University has been testing a variety of medications in search of a compound with demonstrated effects on marijuana abstinence and withdrawal. A study published online last year examines the effectiveness of a variety of medications on the course of marijuana craving and withdrawal in users classified as marijuana dependent. In other words, they are looking for the equivalent of a nicotine patch for marijuana.

In an article for CNS Drugs, Ryan Vandrey of Johns Hopkins University School of Medicine and Margaret Haney of the New York State Psychiatric Institute, surveyed such studies as presently exist on the subject of pharmacotherapy for cannabis dependence. There are presently no clinically validated treatments for marijuana withdrawal. And, unlike the hundreds of controlled, double blind trials of pharmaceuticals for addiction to alcohol, cigarettes, cocaine, and heroin, recent research on medications for marijuana dependence has been sparse and scattershot.

 Nonetheless, the marijuana withdrawal syndrome is now well established in the scientific literature, as well as anecdotally.  Among heavy dope smokers, the authors write, cold-turkey cessation from marijuana “produces cellular changes in the brain reward pathway (increased corticotrophin-releasing factor, decreased dopamine) that have been linked to the dysphoric effects associated with withdrawal from drugs such as alcohol, opiates, and cocaine, and are thought to contribute to relapse.”

What have they discovered so far?

One obvious starting point was dronabinol, a.k.a. Marinol, the government-approved synthetic THC often prescribed for nausea, vomiting, and appetite loss due to chemotherapy. Marinol is a direct approach to the nicotine patch strategy: A substance that stimulates cannabis receptors in a manner similar to, but by no means identical with, the high produced by natural marijuana. Perhaps a regular low dose of Marinol would keep the cannabis cravings at bay among problem users trying to quit. As it turns out, not really. Some studies showed that you could reduce a pot addict’s withdrawal symptoms somewhat in a home environment with Marinol, but the dose required to accomplish this was high enough to represent potential problems of its own.

Another obvious candidate for investigation was rimonabant, a.k.a. Accomplia—but for the opposite reason. Rimonabant, which started out life as an anti-obesity medication, blocks the cannabinoid receptor CB1, so in that sense it should function roughly like Antabuse for alcoholics. It is the “anti-weed,” but as it turned out, rimonabant’s effect on cannabis receptors didn’t do the trick, either. Rimonabant “reduced the effects of smoked cannabis in two studies,” Vandrey and Haney write, “but a reduction of subjective drug effects was not consistently observed.” Furthermore, rimonabant is under suspicion for causing “adverse psychiatric effects” and is not much in favor at present.

Next up, naltrexone—an opiod receptor antagonist, which blocks the effects of heroin and is used in alcohol and heroin detox and withdrawal. Naltrexone has been shown in some studies to “reduce the subjective effects of cannabinoids in humans,” the authors note. But no dice: “In cannabis users, pretreatment with high doses of naltrexone (50-200 mg) failed to attenuate, and in some cases enhanced, the subjective effects of dronabinol and smoked cannabis.” To make matters worse, “the effect of naltrexone can be overcome with higher doses of cannabis.”

Other possible anti-craving drugs for marijuana have not been as rigorously studied. An open-label investigation of buspirone, which works on serotonin and dopamine systems, caused a decline in self-reported cannabis use, and pot smokers showed marked decreases in craving and irritability—but, as these things often go, buspirone was not well-tolerated by the participants, with too many dropouts due to adverse side effects.

Lithium, a mood stabilizer commonly prescribed for bipolar disorder, has shown promise in several small studies. An open-label lithium trial by the National Drug and Alcohol Research Centre in New South Wales resulted in “significant reductions in symptoms of depression and anxiety and cannabis-related problems.” More studies are needed.

Fluoxetine, better known to the world as Prozac, has been anecdotally associated with reduced marijuana use in depressed alcohol-dependent patients, but has never been the subject of any large clinical studies with a population of users whose primary drug is marijuana.

And finally, there is a dark-horse candidate, a treatment drug sometimes employed to prevent relapse

 in cases of heroin addiction. Lofexidine is an alpha-2-adrenergic agonist that has been in use for years in the U.K. under the name BritLofex to treat the common symptoms of heroin withdrawal, such as cramps, chills, sweating, loss of appetite, and diarrhea. Similar but less intense withdrawal symptoms also afflict heavily addicted marijuana users. In a 2008 paper published in Psychopharmacology, “lofexidene was sedating, worsened abstinence-related anorexia, and did not robustly attenuate withdrawal, but improved sleep and decreased marijuana relapse.” Lofexidine combined with THC yielded even better results.

It appears that immediate research might be most profitably focused on lofexidine and lithium. And indeed, additional studies of the two drugs for cannabis dependency are planned by NIDA.  Also, the combination of dronabinol and lofexidine appears to be worth pursuing in future clinical investigations of anti-craving drugs for marijuana.

Vandrey, R., & Haney, M. (2009). Pharmacotherapy for Cannabis Dependence CNS Drugs, 23 (7), 543-553 DOI: 10.2165/00023210-200923070-00001

Graphics Credit: http://archives.drugabuse.gov

Marijuana Withdrawal Rivals Nicotine

Kicking pot or cigarettes leads to anxiety, sleep problems.

A small study in the journal Alcohol and Drug Dependence likened withdrawal from cannabis to that of withdrawal from nicotine, in the case of smokers addicted to either or both substances. The study gave further support to the growing body of evidence supporting the existence of a clinically significant marijuana withdrawal syndrome in heavy marijuana smokers.

As one cigarette smoker in withdrawal famously put it, “I cannot think, cannot concentrate, cannot remember.” Now it appears that heavy marijuana smokers who go cold turkey might be susceptible to the same symptoms of withdrawal from addiction.

Dr. Ryan Vandrey, a professor of psychiatry at Johns Hopkins School of Medicine, and principle author of the study, told Amy Norton of Reuters Health that marijuana withdrawal can cause symptoms similar to nicotine withdrawal, such as anxiety, irritability, difficulty concentrating, and sleep problems. Marijuana withdrawal, which typically affects only heavy smokers, has not been well studied or characterized in the scientific community. Some marijuana advocates view the idea of marijuana withdrawal with considerable skepticism. “These new findings give some idea of its significance,” Vandrey said, and will help inform heavy pot smokers about the symptoms they may face if they abruptly stop smoking.

In the journal article, “A within-subject comparison of withdrawal symptoms during abstinence from cannabis, tobacco, and both substances,” Vandrey and his co-authors conclude: “Overall withdrawal severity associated with cannabis alone and tobacco alone was of a similar magnitude. Withdrawal during simultaneous cessation of both substances was more severe than for each substance alone, but these differences were of short duration and substantial individual differences were noted.”

The authors argue that “cannabis withdrawal is clinically important and warrants detailed description in the DSM-V and ICD-11.” The DSM-V and the ICD-11 are standardized diagnostic classification systems used in the practice of psychiatry.

Participants in the study smoked marijuana at least four times a day, and cigarette smokers consumed 20 or more cigarettes daily.

Since, as Vandrey notes, the presence of withdrawal symptoms often leads to failure when smokers are attempting to quit, it is possible that many more people are trying—and failing—to quit marijuana than researchers have previously suspected. Dr. Vandrey suggested that since difficulty sleeping is one common symptom of withdrawal, sleep medications might be indicated in the case of severe marijuana withdrawal, but cautioned that more study is needed.

Along with insomnia and anxiety, heavy marijuana smokers often report an increase in the frequency and vividness of their dreams during withdrawal as well.

Photo: ©http://www.xes.cx/

See also: Marijuana Withdrawal nicotine

Marijuana Withdrawal Revisited

Is cannabis addictive?

See also Marijuana Withdrawal


Until recently, there was very little evidence in animal models for marijuana tolerance and withdrawal, the classic symptoms of addiction. For at least four decades, million of Americans have used marijuana without clear evidence of a withdrawal syndrome. Most recreational marijuana users find that too much pot in one day makes them lethargic and uncomfortable. Self-proclaimed marijuana addicts, on the other hand, report that pot energizes them, calms them down when they are nervous, or otherwise allows them to function normally. They feel lethargic and uncomfortable without it. Heavy marijuana users claim that tolerance does build. And when they withdraw from use, they report strong cravings.

While the scientific evidence weighed in against the contention that marijuana is addictive, there were a few researchers who were willing to concede the possibility. “Probably not, for most people,” a researcher at the University of Minnesota’s Chemical Dependency Program told me in the late 1990s. “But there may be some small percentage of people who are on the same wavelength with it chemically, and who end up in some way hooked to it physically. It’s a complicated molecule.”

The difference between animal models and humans may be the difference between pure THC and naturally grown marijuana. Despite the fact that rats and monkeys find whopping doses of synthesized THC aversive in the lab, psychopharmacologist Ronald Siegel, in his book Intoxication, has documented numerous instances of rodents feeding happily on wild marijuana plants in the field. There are apparently other components in the psychoactive mix that makes marijuana what it is. When the lab version of THC is hundreds of times more potent that the genuine article, it is hard to know exactly what the research is telling us.

Some of the mystery of cannabis was resolved after researchers demonstrated that marijuana definitely increased dopamine activity in the ventral tegmental area of the brain. Some of the effects of pot are produced the old-fashioned way—by means of neurotransmitter alterations along the limbic system’s reward pathway.

A report prepared for Australia’s National Task Force on Cannabis put the matter straightforwardly:

There is good experimental evidence that chronic heavy cannabis users can develop tolerance to its subjective and cardiovascular effects, and there is suggestive evidence that some users may experience a withdrawal syndrome on the abrupt cessation of cannabis use. There is clinical and epidemiological evidence that some heavy cannabis users experience problems in controlling their cannabis use, and continue to use the drug despite experiencing adverse personal consequences of use.

The U.S. government’s essentially unchanged opposition to marijuana research has meant that, until quite recently, precious few dollars were available for pot research. This official recalcitrance is one of the reasons for the belated recognition and characterization of marijuana’s distinct withdrawal syndrome.

To pluck one statistic out of many, representing estimates made in the late 1990s, more than 11 million Americans smoked marijuana regularly in the NIDA-sponsored “National Household Survey on Drug Abuse.” What NIDA has learned about cannabis addiction, according to the principal investigator of a recent NIDA study, was that “we had no difficulty recruiting dozens of people between the ages of 30 and 55 who have smoked marijuana at least 5,000 times. A simple ad in the paper generated hundreds of phone calls from such people” (This would be roughly equivalent to 14 years of daily pot smoking).

There now exists a nice body of clinical trials showing that mice and dogs show evidence of cannabis withdrawal. (For THC-addicted dogs, it is the abnormal number of wet-dog shakes that give them away.) Today, scientists have a much better picture of the jobs performed by anandamide, the body’s own form of THC. This knowledge helps explain a wide range of THC withdrawal symptoms. Among the endogenous tasks performed by anandamide are pain control, memory blocking, appetite enhancement, the suckling reflex, lowering of blood pressure during shock, and the regulation of certain immune responses.

These functions shed light on common hallmarks of cannabis withdrawal, such as anxiety, chills, sweats, flu-like physical symptoms, and decreased appetite. At Columbia University’s National Center on Addiction and Substance Abuse, where a great deal of NIDA-funded research takes place, researchers have found that abrupt marijuana withdrawal leads to symptoms similar to depression and nicotine withdrawal.

In a 2003 research report entitled “Nefazodone Decreases Anxiety During Marijuana Withdrawal in Humans,” published in Psychopharmacology, researchers at the New York State Psychiatric Institute used Serzone (nefazodone) to decrease some symptoms of marijuana withdrawal in human subjects who had been regularly smoking six joints of pot per day. Anxiety and muscular discomfort were reduced, but Serzone had no effect on other symptoms, like irritability and sleep problems. The drug did not alter the perceived effects of marijuana intoxication (the SSRIs didn’t, either). Serzone is another antidepressant, a modest inhibitor of serotonin and norepinephrine, but its mechanism of action is ill defined. It is not in the SSRI or tricyclic families.

To date, there is no effective anti-craving medication approved for use against the marijuana withdrawal syndrome, for addiction-prone individuals unlucky enough to suffer from it.

For more, see earlier posts:

Marijuana Withdrawal

Is Marijuana Addictive?

Photo credit: 2nd International Cannabis and Mental Health Conference Programme