Weed be better off smoking our parents’ pot

We’ve all heard our parents say it*: “Back in my day, dope was much better than it is now. It wasn’t nearly as strong as what you kids smoke today.”

Like much of the advice our parents give us (like always take out your contacts before you go to bed), this one is also true. The THC (tetrahydrocannabinol – the primary psychoactive compound in cannabis) concentration in marijuana has increased by as much as 12% over the last 30 years. This rise in THC levels is related to increases in the subjective ‘high’ feelings associated with smoking cannabis, like changes in perceptual sensations, contentedness, and increased appetite. However, THC is also linked to many of the negative consequences of cannabis use, including risk for dependence, attentional bias or distraction, impaired memory and cognition, and the potential emergence of psychotic symptoms.

Alternatively, CBD (cannabidiol – one of the other major chemicals in cannabis that works by increasing endogenous cannabinoid levels in the brain) is associated with the anxiolytic or anti-anxiety effects of marijuana. Additionally, it is thought to act as a protective factor against many of the negative effects the drug can have, including the development of abuse, cognitive impairments, and even psychotic symptoms.

Unfortunately, in addition to the high levels of THC seen in today’s cannabis, there is also a significant depletion of CBD. ‘Skunk’, as it is referred to by users and dealers alike, is the strain of this new high-THC, low-CBD cannabis that is flooding the marijuana market. And it is this drug that is thought to be at the root of the increase in cannabis dependence diagnoses seen over the last decade.

Recent changes in policy and public perception of the risks associated with cannabis have also resulted in an increase in use, particularly among adolescents and young adults, with roughly 50% of high school students reporting having used the drug at some point in their lives. However, despite a previous belief that cannabis was not addictive, there has also been a substantial increase in the number of users seeking treatment for dependence, and nearly 11% of current users qualify as addicted. Skunk smokers in particular are more likely to experience cravings for the drug, go through their stash in shorter amounts of time, and have greater attentional bias to cannabis cues.

Professor Val Curran’s group from University College London has been leading the charge on research into the effects of cannabis use, comparing recreational and chronic smokers, and studying the varying effects different strains of cannabis have on the brain. Her group is particularly interested in comparing skunk to THC-CBD strains, and they have discovered much of the evidence for the protective effects CBD has against the development of psychosis and dependence. CBD’s action upon the endogenous cannabinoid anandamide seems to be behind the reduction in psychotic experiences in regular smokers, and CBD has even been looked at as a potential treatment for schizophrenia, reducing psychotic symptoms as effectively as some of the anti-psychotic drugs currently prescribed. THC-CBD users also show less distraction to marijuana stimuli than skunk smokers, and they report significantly reduced feelings of craving. There were also no differences in the subjective intoxication effects of smoking either skunk or THC-CBD, indicating it does not alter the psychoactive properties of the drug.

So the question is, where has all the CBD gone? Modern day growing methods using indoor marijuana farms have greatly decreased the risk of detection for cannabis producers by circumventing the need to import cannabis internationally. Cannabis greenhouses also guarantee a more reliable crop, as they are not dependent on changes in weather patterns. However, the 24-hour lighting used in these farms results in an inadvertent destruction of the CBD levels in the plant. Thus, these new strains not only have increased potency with higher THC contents, they also have reduced protective factors against the drug’s negative effects. In the producers’ eyes, these are just additional economic advantages to growing on an indoor farm, as more dependent users who go through the drug more quickly will result in more cannabis being sold.

These changes in potency raise interesting questions regarding the recent legalization of recreational and medicinal marijuana use in some states. Most pressingly, where and how is this cannabis being produced? And what are the differing levels of THC and CBD present in it? Also, would it be possible to better control cannabis production to avoid its addictive or psychotic-inducing effects? And should we start to think about prescribing CBD to patients currently suffering from THC dependence?

While the developments in cannabis policy may potentially reduce the harm caused to individuals from incarceration or criminal records for minor possession, in terms of the potential psychological effects caused by the drug, it appears we’d be better off smoking our parents’ pot.

*Apologies to my parents, who have never actually uttered the above phrase.

**Title pun credit to Claire Gillan.

8 thoughts on “Weed be better off smoking our parents’ pot

  1. Further justification for the legalisation of the Mary Jane: take the money out of the dealers’ pockets, wipe the blood off their hands and put the CBD back in alongside the THC. Unfortunately, as Prof. David Nutt discovered, facts relating to health play second fiddle to election vote winning hyperbole.

  2. The increases in THC content are overblown. While THC content in marijuana seized by police increased from 6.5% in 1980 to 9.2% in 1996 and 11.2% in 1997, the increases are primarily due to an increase in hydroponic production. Marijuana grown outdoors contains generally the same amount of THC.

    That said, hydroponic production is increasing, specifically in those states that permit medical marijuana use.

    But, hash and hash oil has been available since our parent’s days. Both containing higher levels of THC than the marijuana people smoke.

    More importantly, experienced marijuana smokers are able to adjust their smoking behavior to obtain the desired level of high. Thus, when smoking higher potency marijuana, smokers have a tendency to decrease the amount of marijuana they inhale.

    The science regarding increased likelihood of addiction is not persuasive. It is likely that the increased levels of THC are non-threatening and perhaps even beneficial, allowing people to inhale less carcinogenic marijuana smoke to obtain the same level of high.

    Iverson, The Science of Marijuana (2000). pp. 223-226

    • Thanks for your comment. You may be right about the changing THC levels, I’m afraid I’m no expert in the matter. However, the UK has released reports of seized skunk cannabis with 14% THC content in 2007, which is more than twice as strong as what you reported being seized from 1980.

      Also, the change in self-administration of the drug is not necessarily effective at reducing overall intake. While initially individuals might decrease their use to adjust for the increased potency, over time cannabinoid receptors in the brain will experience tolerance to the increasing levels of the drug, making them less sensitive. Therefore the user will require greater amounts to achieve the same level of high. I would expect this to especially be true if the cannabis was particularly potent, as the receptors would adjust more quickly to the dramatic increases in CB receptor excitation, though this is just an assumption.

      Also, the bigger problem is not the increasing THC levels, but the absence of CBD, which can serve as a protector against even higher quantities of THC and their potential negative effects. This seems to be the largest and most harmful change from natural outdoor production to hydroponic farms.

  3. THC levels have increased two to four fold and CBD has all but disappeared in some strains. Your analysis of these developments is correct but your assessment of the consequences is not. the number of people experiencing any mental health problems at all is tiny. The main danger is for children which is the primary argument for taking the market out of the hands of criminals.

    You should look at the NTA and HES fifures for those in treatment and admitted to hospital. Although individual caes are cleary personal tragedies they are very, very rare. While there are 750 hospital admissions for mental and behavioural problems related to cannabinoids each year, thehre are 3000 admissions for peanut allergy.

    In public health terms cannabis is a trivial, almost non-existent problem yet we spend £500 million each year on the criminal justice system in a futile attempt to stamp it out. This is the real cannabis psychosis.

    • Hi Peter, thanks for your comment.

      You’re right, despite the media hype, psychosis is really not a major concern for cannabis smokers, affecting only a very small percentage. And even then it’s unknown whether a predisposition for psychosis was underlying and even facilitating self-medication with cannabis, increasing the association between the two.

      I think the larger concern now is the issue of dependence on the drug. Cannabis itself is relatively safe, with extremely low toxicity levels and almost no severe side effects. However, there is a true concern regarding the increase in cannabis dependence, particularly among adolescent males, with roughly 11% of users qualifying as dependent according to DSM criteria. This is most likely due in part to the increase in THC and decrease in CBD levels seen over the last few decades. While the vast majority of users will still experience no serious side effects from smoking cannabis, with decriminalization of the drug it is important to consider those who may have problems with it. Cannabis dependence is often dismissed as not being a ‘serious’ addiction, but it does affect a significant number of users and needs to be acknowledged and adequately addressed.

      That being said, I agree that the amount of money spent on policing the marijuana trade is horrendous, and by legalizing and controlling the market you could do away with these high THC strains and introduce quality control measures. Instead of spending money on incarcerations and fighting drug cartels, these funds would be much better spent on helping those who do have a problem with the drug, and better controlling and educating those who choose to use it.

  4. The Israeli company responsible for developing Avidekel (pictured above), Tikun Olam , is not the first to breed a strain of cannabis that contains almost no THC at all. In 2005, GW Pharmaceuticals (creator of Sativex ) grew “virtually mono-cannabinoidic plants that produce high percentages of these target cannabinoids: THC, CBD, THC-V, CBC, CBD-V, CBG or CBN.” Project CBD tested 17 different mothers of Cannatonic – a strain famous for its high CBD levels. Cannatonic #6 was high in CBD with hardly any THC, whereas the other plants were high in THC and low in CBD or high in both. Perhaps the great variety of results from different plants was because the Cannatonic strain is unstable, or perhaps people were getting different results from different growing conditions.

  5. Pingback: Cannabis and memory loss: dude, where’s my CBD? | Brain Study

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