In this episode, my guest is Dr. Matthew Hill, Ph.D., a professor of cell biology and anatomy at the Hotchkiss Brain Institute at the University of Calgary and an expert on the biology of cannabis. We discuss how cannabis affects the brain to produce its psychoactive effects (feeling “high”), including altered time perception, focus, memory, appetite, and stress.
We discuss how THC vs. cannabidiol (CBD) affects the brain, the effects of different routes of cannabis administration (e.g., smoking, vaping, edibles), high-potency THC, and whether cannabis is addictive. We discuss if there is a link between cannabis use and the development of psychosis, anxiety, bipolar depression, or schizophrenia.
We discuss whether CBD has clinical benefits in regulating stress, promoting sleep, and treating certain diseases. We also discuss if there are real and consistent differences in the biological effects of different cannabis strains, if cannabis impacts hormones, and the uses of cannabis for the management of pain, stress, Post-traumatic stress disorder (PTSD), anxiety, and nausea.
Listeners of this episode will get an up-to-date understanding of what is currently known about how cannabis affects the brain and body, including both its potential benefits and risks.
The article titled “Cannabis and Psychomotor Performance: A Rational Review of the Evidence and Implications for Public Policy” discusses the effects of cannabis on psychomotor performance. It suggests that cannabis can impair psychomotor skills for up to 5 hours after consumption. This is important for safety-sensitive activities such as driving or operating machinery. The article also mentions that the degree of impairment can vary depending on the dose and the individual’s tolerance.
Cannabis users also show no difference in motivation for rewards, pleasure taken from rewards, or the brain’s response when seeking rewards, compared to non-users.
Cannabis is the third most commonly used controlled substance worldwide, after alcohol and nicotine. A 2018 report from the NHS Digital Lifestyles Team stated that almost one in five (19%) of 15-year-olds in England had used cannabis in the previous 12 months, while in 2020 the National Institute on Drug Abuse reported the proportion in the United States to be 28% of 15-16-year-olds.
A common stereotype of cannabis users is the ‘stoner’ – think Jesse Pinkman in Breaking Bad, The Dude in The Big Lebowski, or, more recently, Argyle in Stranger Things. These are individuals who are generally depicted as lazy and apathetic.
At the same time, there has been considerable concern of the potential impact of cannabis use on the developing brain and that using cannabis during adolescence might have a damaging effect at an important time in an individual’s life.
A team led by scientists at UCL, the University of Cambridge and the Institute of Psychiatry, Psychology & Neuroscience at King’s College London carried out a study examining whether cannabis users show higher levels of apathy (loss of motivation) and anhedonia (loss of interest in or pleasure from rewards) when compared to controls and whether they were less willing to exert physical effort to receive a reward. The research was part of the CannTEEN study.
The results are published in the International Journal of Neuropsychopharmacology.
The team recruited 274 adolescent and adult cannabis users who had used cannabis at least weekly over the past three months, with an average of four days per week, and matched them with non-users of the same age and gender.
Participants completed questionnaires to measure anhedonia, asking them to rate statements such as “I would enjoy being with family or close friends”. They also completed questionnaires to measure their levels of apathy, which asked them to rate characteristics such as how interested they were in learning new things or how likely they were to see a job through to the end.
Cannabis users scored slightly lower than non-users on anhedonia – in other words, they appeared better able to enjoy themselves – but there was no significant difference when it came to apathy. The researchers also found no link between frequency of cannabis use and either apathy or anhedonia in the people who used cannabis.
Martine Skumlien, a PhD candidate in the Department of Psychiatry at the University of Cambridge, said: “We were surprised to see that there was really very little difference between cannabis users and non-users when it came to lack of motivation or lack of enjoyment, even among those who used cannabis every day. This is contrary to the stereotypical portrayal we see on TV and in movies.”
In general, adolescents tended to score higher than adults on anhedonia and apathy in both user and non-user groups, but cannabis use did not augment this difference.
Dr Will Lawn, from the Institute of Psychiatry, Psychology and Neuroscience at King’s College London, said: “There’s been a lot of concern that cannabis use in adolescence might lead to worse outcomes than cannabis use during adulthood. But our study, one of the first to directly compare adolescents and adults who use cannabis, suggests that adolescents are no more vulnerable than adults to the harmful effects of cannabis on motivation, the experience of pleasure, or the brain’s response to reward.
“In fact, it seems cannabis may have no link – or at most only weak associations – with these outcomes in general. However, we need studies that look for these associations over a long period of time to confirm these findings.”
Cannabis users no less likely to be motivated or able to enjoy life’s pleasure https://link.researcher-app.com/nEsd – via Researcher (@ResearcherApp)
Chronic adolescent exposure to ?-9-tetrahydrocannabinol (THC) is linked to elevated neuropsychiatric risk and induces neuronal, molecular and behavioral abnormalities resembling neuropsychiatric endophenotypes. Previous evidence has revealed that the mesocorticolimbic circuitry, including the prefrontal cortex (PFC) and mesolimbic dopamine (DA) pathway are particularly susceptible to THC-induced pathologic alterations, including dysregulation of DAergic activity states, loss of PFC GABAergic inhibitory control and affective and cognitive abnormalities. There are currently limited pharmacological intervention strategies capable of preventing THC-induced neuropathological adaptations. l-Theanine is an amino acid analog of l-glutamate and l-glutamine derived from various plant sources, including green tea leaves. l-Theanine has previously been shown to modulate levels of GABA, DA, and glutamate in various neural regions and to possess neuroprotective properties. Using a preclinical model of adolescent THC exposure in male rats, we report that l-theanine pretreatment before adolescent THC exposure is capable of preventing long-term, THC-induced dysregulation of both PFC and VTA DAergic activity states, a neuroprotective effect that persists into adulthood. In addition, pretreatment with l-theanine blocked THC-induced downregulation of local GSK-3 (glycogen synthase kinase 3) and Akt signaling pathways directly in the PFC, two biomarkers previously associated with cannabis-related psychiatric risk and subcortical DAergic dysregulation. Finally, l-theanine powerfully blocked the development of both affective and cognitive abnormalities commonly associated with adolescent THC exposure, further demonstrating functional and long-term neuroprotective effects of l-theanine in the mesocorticolimbic system.SIGNIFICANCE STATEMENT With the increasing trend of cannabis legalization and consumption during adolescence, it is essential to expand knowledge on the potential effects of adolescent cannabis exposure on brain development and identify potential pharmacological strategies to minimize ?-9-tetrahydrocannabinol (THC)-induced neuropathology. Previous evidence demonstrates that adolescent THC exposure induces long-lasting affective and cognitive abnormalities, mesocorticolimbic dysregulation, and schizophrenia-like molecular biomarkers that persist into adulthood. We demonstrate for the first time that l-theanine, an amino acid analog of l-glutamate and l-glutamine, is capable of preventing long-term THC side effects. l-Theanine prevented the development of THC-induced behavioral aberrations, blocked cortical downregulation of local GSK-3 (glycogen synthase kinase 3) and Akt signaling pathways, and normalized dysregulation of both PFC and VTA DAergic activity, demonstrating powerful and functional neuroprotective effects against THC-induced developmental neuropathology.
Among the respondents this study regarded as high cannabis users, however, there was also an increased risk for schizophrenia associated with cigarette smoking (relative risk 6.1) and alcohol consumption (relative risk 6.5). This points to a challenge for such epidemiological studies, namely that it is difficult to separate the effects from cannabis, tobacco, and alcohol because of extensive overlaps in use.
The investigators report for the first time that CBD normalizes levels and function, improving cognition as it also reduces levels of the immune protein IL-6, which is associated with the high inflammation levels found in Alzheimer’s, says Dr. Babak Baban, immunologist and associate dean for research in the Dental College of Georgia and the study’s corresponding author.
“Given the growing challenges in chronic pain management coupled with the ongoing consequences of the opioid epidemic, pain management practitioners are looking into more effective, innovative, and safer alternatives to treat pain. Cannabis-based medicine had been described for hundreds of years but only recently have we seen the more scientific, evidence-based approach to its use, and ongoing investigations continue to explore its potential medical benefits. While historically more attention has been paid to the psychoactive component of the cannabis plant Δ9-tetrahydrocannabinol (THC), there have been fewer scientific studies on the medical use of the cannabidiol (CBD) – a non-psychoactive component of the cannabis plant.”
“Compared to placebo, pretreatment with 300 mg of CBD significantly reduced anxiety during the speech. No significant differences in VAMS scores were observed between groups receiving CBD 150 mg, 600 mg and placebo.”
The Australian Capital Territory has passed legislation to make recreation use and cultivation of cannabis legal as of January 2020! Lets hope this follows a similar path as in the USA and we see other states follow suit now that we have a precedent and model legislation.
It’s 2019 and we still live in a world where one small study, on mice, with a highly questionable methodology, published in a marginal journal, with major flaws, leads to a clickbait media panic.
Shockingly, researchers discovered that the mice given higher doses of CBD showed signs of liver damage within 24 hours. To that end, 75 percent of these animals in the sub-acute phase had either died or were on the verge of death within a few days.
But this panic and misinformation is nothing new—back in 1974, a study conducted at Tulane University supposedly showed that “the active ingredient in marijuana [THC] impairs the brain circuitry,†leading the press to dutifully run articles claiming that pot causes brain damage without a trace of skepticism.
In the last decades, a lot of attention has been paid to the compounds present in medicinal Cannabis sativa L., such as Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), and their effects on inflammation and cancer-related pain. The National Cancer Institute (NCI) currently recognizes medicinal C. sativa as an effective treatment for providing relief in a number of symptoms associated with cancer, including pain, loss of appetite, nausea and vomiting, and anxiety. Several studies have described CBD as a multitarget molecule, acting as an adaptogen, and as a modulator, in different ways, depending on the type and location of disequilibrium both in the brain and in the body, mainly interacting with specific receptor proteins CB1 and CB2. CBD is present in both medicinal and fibre-type C. sativa plants, but, unlike Δ9-THC, it is completely nonpsychoactive. Fibre-type C. sativa (hemp) differs from medicinal C. sativa, since it contains only few levels of Δ9-THC and high levels of CBD and related nonpsychoactive compounds. In recent years, a number of preclinical researches have been focused on the role of CBD as an anticancer molecule, suggesting CBD (and CBD-like molecules present in the hemp extract) as a possible candidate for future clinical trials. CBD has been found to possess antioxidant activity in many studies, thus suggesting a possible role in the prevention of both neurodegenerative and cardiovascular diseases. In animal models, CBD has been shown to inhibit the progression of several cancer types. Moreover, it has been found that coadministration of CBD and Δ9-THC, followed by radiation therapy, causes an increase of autophagy and apoptosis in cancer cells. In addition, CBD is able to inhibit cell proliferation and to increase apoptosis in different types of cancer models. These activities seem to involve also alternative pathways, such as the interactions with TRPV and GRP55 receptor complexes. Moreover, the finding that the acidic precursor of CBD (cannabidiolic acid, CBDA) is able to inhibit the migration of breast cancer cells and to downregulate the proto-oncogene c-fos and the cyclooxygenase-2 (COX-2) highlights the possibility that CBDA might act on a common pathway of inflammation and cancer mechanisms, which might be responsible for its anticancer activity. In the light of all these findings, in this review we explore the effects and the molecular mechanisms of CBD on inflammation and cancer processes, highlighting also the role of minor cannabinoids and noncannabinoids constituents of Δ9-THC deprived hemp.
A new study found that many cannabidiol (CBD) products sold online are labeled with the wrong amount of CBD. The researchers analyzed a total of 84 CBD products that they purchased online and found that 26% contained less CBD than the package suggested, while 43% contained more CBD than the package suggested.
Science is smashing all kinds of negative stigmas that were once thought about cannabis and the cannabis consumer.  Thanks to recent studies, people are re-learning everything they thought they knew about pot.  It is widely thought that “stoners†are “lazy, dumb, unproductive, unsuccessful and (my favorite) unhealthyâ€.  This couldn’t be farther from the truth and […]
Cannabis, or marijuana, has been used for medicinal purposes for many years. Several types of cannabinoid medicines are available in the United States and Canada. Dronabinol (schedule III), nabilone (schedule II), and nabiximols (not U.S. Food and Drug Administration approved) are cannabis-derived pharmaceuticals. Medical cannabis or medical marijuana, a leafy plant cultivated for the production of its leaves and flowering tops, is a schedule I drug, but patients obtain it through cannabis dispensaries and statewide programs. The effect that cannabinoid compounds have on the cannabinoid receptors (CB(1) and CB(2) ) found in the brain can create varying pharmacologic responses based on formulation and patient characteristics. The cannabinoid Δ(9) -tetrahydrocannabinol has been determined to have the primary psychoactive effects; the effects of several other key cannabinoid compounds have yet to be fully elucidated. Dronabinol and nabilone are indicated for the treatment of nausea and vomiting associated with cancer chemotherapy and of anorexia associated with weight loss in patients with acquired immune deficiency syndrome. However, pain and muscle spasms are the most common reasons that medical cannabis is being recommended. Studies of medical cannabis show significant improvement in various types of pain and muscle spasticity. Reported adverse effects are typically not serious, with the most common being dizziness. Safety concerns regarding cannabis include the increased risk of developing schizophrenia with adolescent use, impairments in memory and cognition, accidental pediatric ingestions, and lack of safety packaging for medical cannabis formulations. This article will describe the pharmacology of cannabis, effects of various dosage formulations, therapeutics benefits and risks of cannabis for pain and muscle spasm, and safety concerns of medical cannabis use.
