For many years, cannabis has been categorized by producers and consumers by its physical characteristics and its predicted effects. Even those unfamiliar with cannabis have likely heard the terms “Indica” and “Sativa” used when referring to various cannabis strains. Yet, what do the terms mean, and how did they come to permeate cannabis culture? In terms of drug effects, at least anecdotally, cannabis products classified as Indica are commonly associated with having calming or sedative effects. While conversely, cannabis plants classified as Sativa are associated with greater perceived intoxicating and energizing effects.

Historically, the distinction between Indica and Sativa dates to the late 18th century, when French biologist and taxonomist Jean-Baptiste Lamark received cannabis samples from a colleague in India. While at first glance these new samples had a similar appearance and aroma compared to the Cannabis Sativa samples Lamark had previously studied; he did note distinct differences between the shape of the plant’s leaves, stems, and flowers. In particular, he noted that the samples from India had significantly broader leaves. As a result, he named this new type of cannabis “Indica”, the Latin name for India, from where these samples originated (Erkelens & Hazekamp, 2014). While the terms Indica and Sativa that Lamark coined over 200 years ago have had a lasting impact on how cannabis is still categorized, recent research has shown that these terms largely ignore scientifically derived chemotypes. In other words, these terms do not accurately reflect the diversity of commonly cultivated cannabis. 

Scientifically speaking, a chemotype is a more precise way to identify subspecies of plants that grow, appear, and smell alike but are chemically distinct from each other. Consequently, chemotypes give us a more accurate description of cannabis subspecies and the effects they may have. When looking at the chemotypes of cannabis, the compounds within the plant that contribute to these chemical differences are cannabinoids (i.e., compounds that interact with the body’s endocannabinoid system) and terpenes (i.e., compounds that make up plant essential oils). You’ve probably heard of the two cannabinoids that receive the most attention cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), but there are also terpenes that are commonly included in chemotypes such as alpha-pinene, beta-caryophyllene, and limonene (Atakan, 2012; ElSohly & Gul, 2016). It is the relative amounts and potentially the interaction of these components together, commonly known as the “entourage effect”, that determines the effects of cannabis (Piomelli & Russo, 2016). So, it doesn’t matter if the strain is Indica or Sativa but rather what’s inside the plant itself. That being said, science still has a long way to go in understanding these interactions (Anand, Pacchetti, Anand, & Sodergren, 2021).

In the largest analysis of U.S.-based commercial cannabis of its kind to date, researchers reported that while they could reliably identify various chemotypes across almost 90,000 samples, those chemotypes didn’t consistently align with the commercial labeling of strains such as Indica, Sativa, or hybrid (Smith, Vergara, Keegan, & Jikomes, 2022). Furthermore, other research has shown that the physical characteristics that were originally used to differentiate Indica (broader plant leaf shape) from Sativa (narrower plant leaf shape) from Sativa are no longer consistent within strains. This may be the result of generations of plants crossbreeding (Vergara et al., 2021). This study and many others like it are increasingly telling us that the use of the names Indica and Sativa may not be as meaningful as many people think. Legal markets, like Colorado, that offer cannabis products require that products be labeled with specific information on product content, such as the exact THC content. Because the distinction between chemotype and strain isn’t always clear to consumers, and cannabis products are still primarily marketed by their strain name. Additionally, most states that sell legal cannabis don’t require producers to report full-plant chemotypes, and as a result, other compounds like CBD and terpenes may not be accurately reported or even reported at all. If we can start focusing more on the cannabis chemotype rather than the strain name this could help consumers and researchers more accurately identify cannabis products and their predicted effects. So, the next time you’re picking out a cannabis product don’t ask for Indica or Sativa, but rather, THC or CBD!

Every day we are learning more and more about cannabis thanks to research taking place at centers like CUChange. However, despite our growing knowledge of cannabis, there are still several misconceptions about this increasingly available product. One such misconception is that it is not possible to become addicted to cannabis after periods of prolonged use. In fact, cannabis CAN be addictive.

Cannabis use disorder (CUD) has been a clinically recognized substance use disorder for many years. CUD has been recognized by the American Psychiatric Association since 2013 (APA, 2013) and was also recognized by the World Health Organization starting in 2019 (WHO, 2019). You may now be wondering what does CUD mean and how is it diagnosed? Well, the Centers for Disease Control and Prevention (CDC) defines CUD as an individual being unable to willingly stop the use of cannabis products despite it causing potential health issues and social problems. The diagnosis of CUD involves eleven different criteria including social/interpersonal problems, craving, and withdrawal. Meeting any two of these eleven criteria within the past 12 months constitutes a diagnosis of CUD (APA, 2013; Patel & Marwaha, 2020). The eleven criteria from the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Version 5 (APA, 2013) can be found listed below. * 

1. Cannabis is often taken in larger amounts or over a longer period than was intended. 

2. There is a persistent desire or unsuccessful efforts to cut down or control cannabis use 

3. A great deal of time is spent in activities necessary to obtain cannabis, use cannabis, or recover from its effects. 

4. Craving, or a strong desire or urge to use cannabis 

5. Recurrent cannabis use results in failure to fulfill role obligations at work, school, or home. 

6. Continued cannabis use despite persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of cannabis. 

7. Important social, occupational, or recreational activities are given up or reduced because of cannabis use. 

8. Recurrent cannabis use in situations in which it is physically hazardous. 

9. Cannabis use continues despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by cannabis. 

10. Tolerance, as defined by either: (1) a need for markedly increased cannabis to achieve intoxication or desired effect or (2) a markedly diminished effect with continued use of the same amount of the substance. 

11. Withdrawal, as manifested by either (1) the characteristic withdrawal syndrome for cannabis or (2) cannabis is taken to relieve or avoid withdrawal symptoms. 

*If you are a cannabis user or you start using cannabis and believe you are suffering from any of the symptoms listed above, please contact your primary care physician to discuss these concerns further. 

It is currently estimated that 3 out of 10 individuals that use cannabis have at least some degree of CUD (Hasin et al., 2015). The age demographic that is most affected is 18 to 25-year-olds, with 13.5% of this age group experiencing some symptoms of CUD within the past year (HHS, 2021). In comparison, 15.6% of individuals 18-25 are diagnosed with an alcohol use disorder, according to the 2020 National Survey on Drug Use and Health (HHS, 2021). 

Why does cannabis use disorder occur? 

Cannabinoids like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are just two of the many active compounds found within cannabis products, and it is THC that is commonly associated with producing the intoxicating effects associated with cannabis. One prevailing theory of how cannabis use disorder develops is attributed to THC’s interaction with dopaminergic and serotonin receptors within the brain. Both receptors play a role in the body’s intrinsic reward system and prolonged use of cannabis products high in THC may disrupt how this system functions and produce some of the symptoms of CUD (NIDA, 2016). 

Treatment for cannabis use disorder 

An important component of many of the diagnostic criteria for cannabis use disorder is that cannabis use persists despite the individual’s desire to stop using and despite consequences that may occur with prolonged use. These features are common with other substance use disorders, including alcohol use disorder, stimulant abuse, and opiate abuse. There are currently no approved pharmacotherapies (i.e., medications) for the treatment of cannabis use disorder although some medications may be prescribed to lessen the symptoms of withdrawal (Connor et al., 2021). There are multiple clinical trials currently underway to develop new medications targeted at treating cannabis use disorder (Connor et al., 2021; Sherman & McRae-Clark, 2016). Because we don’t have effective medications yet, treatment relies heavily on talk therapies like cognitive behavioral therapy (CBT), motivational enhancement therapy, and contingency management (Connor et al., 2021). Interestingly, another cannabinoid that we have already mentioned is currently being explored as one of these potential therapy options. Cannabidiol (CBD), unlike THC, is not intoxicating and can antagonize or oppose the effects of THC. This may provide a natural remedy to assist with the treatment of cannabis use disorder, though further research is necessary (Freeman et al., 2020). For those who frequently use high doses of cannabis, withdrawal symptoms may occur when use is stopped or reduced, and these symptoms can include trouble falling asleep, changes in appetite, feelings of aggression or irritability, depressed mood, and headaches (Levin et al., 2010). These symptoms can last 1-4 weeks and be quite distressing to individuals attempting to abstain from cannabis (Budney & Hughes, 2006). Individuals who think they may have CUD should speak to their doctor. 

In conclusion, as you have learned, it is indeed a myth that cannabis is not addictive. Cannabis use disorder is recognized by many health organizations as a substance use disorder and appears to be most prevalent in individuals aged 18 to 25 years old but can afflict people of all ages. Treatment options are available and should be discussed with your primary care physician. Individuals with cannabis use disorder find symptom relief with cessation of cannabis use and supervised medical treatment.

 *The above information is for educational purposes only and should not be considered medical advice. 

Cannabis products come in all shapes and sizes. These products are often broken down into how they are consumed, or how the active ingredients are entering the body. Generally, the two main categories are cannabis products that are consumed orally, better known as edibles, and cannabis products that are inhaled. Both edible and inhaled products contain the same active ingredients, known as cannabinoids, but the way these cannabinoids enter the body to exert their effects is drastically different. 

When cannabis is smoked or vaporized, cannabinoids like delta-9-tetrahydrocannabinol (THC) are released into the smoke or vapor. This allows the smoke to then be inhaled into the lungs where the cannabinoids can be absorbed into the blood (Huestis et al., 1992). This is also a key step in activating cannabinoids like THC. Heating the cannabis flower or bud causes a process called decarboxylation.This process transforms the cannabinoids from their naturally occurring, inactive form to their active form which can interact with various tissues in the body. 

Conversely, most edible products are typically made from a process that uses solvents to latch on to and remove the cannabinoids from the plant. These solvents can then be removed from the cannabinoids to create a purified extract or concentrate (Michalizzi et al., 2021). These concentrates can then be dissolved in oils because cannabinoids, like THC, are lipophilic (McClements, 2020), meaning they dissolve in fats. These extracted cannabinoid compounds can then be made into edible products such as candies or baked goods. It is important to note that although concentrate products are described here pertaining to edible consumption specifically, another common route of administration for concentrates is inhalation. 

Fun Fact: Did you know that approximately, 4.81 million edible cannabis products are sold in the state of Colorado each year? This accounts for nearly 45% of all cannabis sales in the state! That’s a lot of candy. 

Which type of product is safer, edible or inhaled?

Instinctively, you may think that edible products are safer. You may associate inhaled cannabis products with tobacco cigarettes, and we all know the negative impact tobacco use can have on our health. This may come as a surprise, but the answer of which is safer isn’t as cut and dry as you might expect. 

Inhaled Products 

Research has shown that a single use of cannabis can provide short-term bronchodilatory effects, meaning it helps expand the airways allowing air to flow easier into and out of the lungs. It is for this reason that cannabis has been used as a treatment for asthma since the 19th century (Kaplan, 2021). However, these effects subside after only a couple of hours. Long-term cannabis use via inhalation may be less beneficial. One study, published in 2022, found that cannabis use was associated with reduced lung function. Yet, the authors do note that this was largely due to cannabis users having larger lung volumes than their non-user counterparts. It was also noted that the major impact of inhaled cannabis use on respiratory health may be the result of impaired gas transfer between the lungs and the blood (Hancox, 2022). The precise mechanism of action of inhaled products has not yet been fully discovered and may indeed vary depending on the method of use. There are a variety of ways to inhale cannabis including joint, bong, pipe, vape, dabs, and blunts, but it is still uncertain if one or more of these methods carries more risk than any of the others. 

Edible Products 

So far it has been difficult to fully assess whether edible products consumed as intended have side effects similar to or different from inhaled products. This is in part due to most of the research exploring edible products being done with relatively low doses in a controlled, clinical setting. In this controlled environment, it is difficult to evaluate the real-world risks of edibles. For example, the major risk of edible products come with ingesting too much, and that’s something we can’t evaluate in a clinical research study. 

It’s also challenging to test the effects of higher doses of THC or the presence of contaminants, as it wouldn’t be ethical to give participants higher doses of THC than they were used to or give them contaminated edibles. Luckily, there is ongoing research at CUChange in Boulder, CO that is exploring and assessing the use of edible products in a more practical, real-life setting outside the walls of a laboratory. In this center, research participants consume self-selected doses of edible products inside their own homes and then complete assessments for a variety of psychological and physiological variables (Bidwell et al., 2022). 

Another aspect of edibles to take into consideration is the fact that most of these products are sold as chocolate, gummies, brownies, and cookies. These products may be easily mistaken for non-cannabis products, particularly by children. It is therefore especially important to ensure that these products are kept out of reach of children to avoid inadvertent intoxication. A study conducted analyzing phone calls to the Oregon/Alaska Poison Center over 2 years found that 28% of these calls were for children under the age of 12 years old who had accidentally ingested edible cannabis products (Noble et al., 2019). In addition, research suggests that the rate of these accidental exposures may be increasing (Chao et al., 2016). 

How long does it take to feel the effects? 

One final aspect to take into consideration when comparing edibles to inhaled products is the time it takes for them to enter your system and start exerting effects. The route for inhaled products to enter your system is much more direct than it is for edible products. When the smoke from inhaled products enters your lungs, it can directly diffuse from your lungs into the blood. The cannabinoids in your blood are then circulated throughout your body and can exert their effects. These effects can be felt very quickly and usually peak within approximately 15-minutes (Spindle et al., 2021). While the effects of inhaled products are quick to take effect, their effects also dissipate rather quickly. 

Edibles on the other hand take effect much slower. Peak intoxication with edibles can take anywhere from 1-2 hours with the intoxicating effects lasting much longer than inhaled products (Spindle et al., 2021). Because edibles can take so long to take effect, it’s not uncommon for individuals to get impatient and consume more product before their first edible takes full effect. This can lead to over-intoxication and an overall bad experience. Although there are no reported deaths caused solely by acute cannabis toxicity, exposure to too much cannabis is associated with negative effects. Symptoms of acute cannabis toxicity may include drowsiness, tachycardia (an unusually fast heart rate), agitation, confusion, nausea, and vomiting (Noble et al., 2019). 

Conclusions 

In summary, edibles may be more likely to lead to accidental overexposure and thus negative effects. Because of this, even though there may be some negative effects associated with inhaled products, it would be overly simplistic to make a blanket statement that edibles are safer than inhaled forms of cannabis. Context is important when deciding what route of administration to use. If use is for medical purposes, individuals should work with their medical care team and/or someone knowledgeable about cannabis products to decide what product type will minimize the risk of unwanted effects. 

Some people believe that the use of cannabis should be avoided because it will “fry your brain,” but what does the term “fry” really mean? Our best interpretation of this term and phrase is that it implies that the use of cannabis, either short-term or long-term, will have detrimental effects on the brain and how it functions. While this phrase is quite common and can be used as a scare tactic to dissuade people from using cannabis it does raise the question - is there any scientific merit to it? Short and Long-Term Effects Research has observed that the acute use of cannabis does indeed reduce performance on tasks involving memory, cognitive control, and learning (Volkow et al., 2016). However, the deficits observed following a single, acute use of cannabis appear to be temporary, with the effects wearing off after cannabis intoxication subsides (Volkow et al., 2016). While the cognitive deficits observed with acute use appear to only be temporary, of greater public health concern are the effects of frequent, prolonged cannabis use. While the observed effects are minor, it has been shown that chronic cannabis users have impaired function in a wide variety of cognitive tasks compared to non-users (Grant et al., 2003, Scott et al., 2018). It is important to note that the effects of cannabis on cognition appear to depend on the dosage and timing of cannabis use. In addition, it is challenging to account for other factors (such as the use of other drugs and alcohol) that may at least partially account for cognitive differences between cannabis users and non-users. Finally, these effects are dependent on the individual and can vary from person to person. 

Cannabis Use in Adolescents 

The largest impacts on cognition and brain development are observed in frequent cannabis users and in individuals who started using as adolescents. When combining results across all studies, there are minimal decreases in IQ (~2 IQ points) among those who have tried or used cannabis; however, these decreases are larger and more significant among adolescents who frequently used cannabis or met cannabis dependence criteria (Power et al., 2021). But why is this? Our body naturally produces compounds known as endocannabinoids that interact with a variety of receptors spread throughout the body that make up what is known as the endocannabinoid system. The endocannabinoid system is heavily localized in the brain, and adolescents (people aged 10 through 19) may be at particular risk for cognitive impairment, due to the prominent role that the endocannabinoid system has in neural development and brain maturation (Lubman et al., 2015). 

Are the Effects Permanent? 

Many studies on adult cannabis users indicate that memory and learning impairments are not permanent and dissipate after a period of time once cannabis use has ended (Scott et al., 2018). One such study looked at brain volume reductions in chronic cannabis users and found that participants who use products containing CBD or completely abstain from cannabis use for a few months have similar brain volumes when compared to non-users (Yücel et al., 2016). Other work found that performance on cognitive tasks returns to the same level as non-users after abstaining from cannabis. There is some discrepancy in how long this abstinent period should be to observe these effects, but estimates range from 3 to 25 days (Scott et al., 2018; Schreiner and Dunn, 2012). Unfortunately, there is still little known about the reversibility of these effects when cannabis use starts during adolescence. A study from 2010 observed that adolescents who had abstained from cannabis use for at least 5-weeks still had cognitive impairments on a memory task compared to non-users (Jager et al., 2010). This suggests that the cognitive impairments associated with adolescent cannabis use are either not reversible or take longer to remediate compared to adults (Hurd et al., 2019). More research is still needed to fully explain these effects. 

Conclusions 

While it might be a bit of a stretch to say that using cannabis will “fry your brain,” research does show that both the acute and prolonged use of cannabis may have detrimental effects on the brain and how it functions. Luckily, in adult cannabis users these effects appear to be minor and typically reverse with the cessation of cannabis use; however, this may not be the case in individuals who start using in adolescence. Because of these observations, it is not recommended for individuals under the age of 21 to consume cannabis products.