« Back to Winter 2012

Darren M. Roesch, Ph.D.,<br />A Professor of Pharmacology Speaks...


Darren RoeschSixteen states and the District of Columbia have now outlawed criminal penalties when marijuana, or cannabis, is used for medical purposes. As a result of this rapidly changing political and legal landscape, it is a growing concern among educators and health care professionals that the increasing recognition of marijuana, or cannabis, as a medically beneficial substance will cause some to believe mistakenly that marijuana is safe. Given the potent physiological and psychological effects of this drug, a mistaken belief in its safety could lead to increased abuse and subsequent individual and societal harm.

It is essential that our students learn that just because the law is beginning to recognize certain medical benefits of marijuana, this does not mean that marijuana is safe to be used freely. Like all substances that we take into our bodies, we need to make sure that we take them into our bodies for the right reasons. This is equally true for broccoli, meat, chocolate, aspirin, or any of the “dietary supplements” that are readily marketed for treating various health conditions without their effectiveness and safety ever having been evaluated by a government agency.

A substance that is as powerful and has as many effects on our minds and bodies as marijuana, needs to be used under the close supervision of a medical professional in order to ensure its effectiveness and safety. Remember, medical marijuana is a prescription drug in the states where it is legally available.

This article will discuss the components of marijuana, how it works once inside the body, the importance of using a drug properly, the ability of marijuana to cause addiction, synthetic marijuana, effects of cannabinoids on the body, and teaching our students appropriate coping skills.


Marijuana is an herbal preparation collected from the flowering tops, leaves, stalks, and seeds of the plant, Cannabis sativa. The herbal preparation contains over 400 compounds and over 60 of these chemical compounds are known as cannabinoids and are unique to the plant genus Cannabis. The most potent psychoactive substance among these cannabinoids is Δ9-tetrahydrocannabinnol (THC), and the non-cannabinoid constituents of the plant are similar to those compounds found in tobacco, except there is no nicotine.


There are specific molecular “receptors” for cannabinoids on the surface of cells throughout the body. Cannabinoids bind these receptors and cause changes in the way the cell works through chemical changes that occur in response to the binding of the chemical to the receptor. CB1 receptors are expressed highly in the central nervous system and regulate many physiological processes such as energy balance and blood vessel constriction and relaxation and are also responsible for most of the psychotropic effects of the cannabinoids. CB2 receptors are concentrated in the spleen, tonsils, and thymus and are recognized for their involvement in regulation of immune system function.

Like the opioids, we now know that these cannabinoids that are derived from plants found outside our bodies are acting on receptors that are meant for different chemicals that are made naturally, inside our bodies. Actually, all drugs have their effects by interacting in some way with the body’s natural function. In the case of the cannabinoid receptors, an endogenous chemical that the plant-derived cannabinoids is mimicking was first isolated in the 1992 and was named anandamide after the Sanskrit word for bliss, ananda. A second endogenous cannabinoid called 2-arachidoyl glycerol (2-AG) was isolated in 1995. There may be other cannabinoids that are endogenously produced by our bodies.

But there is one important difference in the way cannabinoids from the cannabis plant and anandamide and 2-AG have effects on our bodies. When our bodies make, use, and respond to anandamide and 2-AG they do so in very carefully regulated processes that have developed evolutionarily over more than 500 million years. In contrast, when we ingest these compounds that we find outside of our bodies, we are controlling the way these receptors on our cells get stimulated.


Pharmacologists and health care professionals know that sometimes it is beneficial to take something from outside our bodies and use it to mimic the way natural substances in our bodies work. However, it is very difficult to do this effectively and safely. We know that these substances from outside our bodies work best when we use them in the same ways our bodies would use the substances they naturally make, but unfortunately we still know very little about how most substances in our bodies are made and work. Therefore, we really aren’t capable of using them as properly as our body’s naturally produced substances. To be frank, even doctors know very little about how drugs work on our bodies. Luckily, they know more than the average guy on the street, and they are trained to help you use these drugs in the safest and most effective manner possible. Therefore, people who are using substances like marijuana need to use them with the help of well-trained medical professionals.


An example of the why it is so important to know how to use a drug properly is illustrated by the story of insulin and diabetes. Sir Frederick Banting discovered that people with diabetes were accumulating sugar in their blood, were excreting this excess sugar in their urine, and were wasting away because their pancreases no longer produced the hormone insulin that is essential for allowing our bodies to use the sugars, our primary source of energy. We soon learned that we could take insulin from animal pancreases or make it in the laboratory and give it to the person who could not make insulin on their own. This helped a lot of people live longer and healthier lives. Still, diabetics receiving insulin, developed serious complications such as blindness, and heart and kidney diseases, associated with imperfectly regulated blood sugar. Subsequently, we learned that we could prevent many of these complications by more closely mimicking the way natural insulin worked in the body. We are still not able to deliver insulin as effectively as the human body, and people still develop complications from improperly blood regulated blood sugar levels. We may never know how to deliver insulin as effectively as the human body, just as we may never know how to use marijuana as safely and effectively as the human body can use cannabinoids.

In fact, the case is even scarier with marijuana. We know even less about how cannabinoids work on the body than we know about insulin, but we do know that cannabinoids have the ability to make us want even more cannabinoids because they have “incentive salience”. Thus, marijuana has the ability to become a bit of a parasite, making us use it and crave and create even more of it, all for its own benefit and not ours. If you think it is scary to trust people on the internet because they might trick you, you should be even more afraid of the cannabinoids because they can trick you without you even being aware of what they are up to.


As we realize that cannabinoids have the ability to trick our brains into wanting even more cannabinoids, this causes us to ask the question, “why?”. The answer is that these compounds, as well as many ingested substances, can cause addiction.

Addiction is really a brain disease. Some have argued that addiction, like all behaviors, is a choice. For example, if you put a drink of alcohol in front of an alcoholic, he will take a drink despite whatever effects it might have on his life, and some would say that this is his choice. But if you pull out a gun when you present the alcohol, and tell him that he will be shot if he takes a drink, he will be able to abstain from taking a drink. This scenario is often used to argue that alcoholic addiction is choice and not a disease. But this choice experiment elevates the decision to take a drink to extremely high level, namely the importance of very survival. Normally, the decision of whether to take a drink is driven by more mundane brain processes that are mistaken as decisions that are beneficial for our very survival.

Although quite complex, incentive sensitization theory stresses that our bodies have certain “wants’. We may, for example, want sugar for energy. If we eat a ripe, red, sweet strawberry, our want is met and this causes specific brain signaling, particularly in the mesolimbic dopamine system. If that strawberry is particularly good at satisfying our body’s want, that strawberry will have “incentive salience” and our brain will instruct our behavior to obtain more strawberries to satisfy that want. Under ideal conditions, this primitive want would be under the control of our more advanced frontal cortex brain structures. Therefore, one might be able to say that strawberries stain my lips red, and my friends don’t want to kiss me when my lips are so red, so I will meet my want for sugar by eating peaches, which do not stain my lips red. Under ideal conditions, this advanced frontal cortex control of the “want” would be able to work, but in addiction, the younger, and more evolutionarily advanced frontal cortical regions of our brain are not able to help us make appropriate choices and are overrun by our older and more primitive “want” regulating subcortical brain structures. As a result, we become subject to “hypofrontality” and “addiction” and we eat strawberries even when they are not good for kiss-ability. The same is true for marijuana. It possesses the ability to make our brains think it is particularly good at satisfying a “want”, even if our frontal cortex realizes that it impairs our ability to safely drive a car.


In addition to the cannabinoids found in the plant, chemists have synthetically made many cannabinoid-like compounds. Many of these cannabinoids have beneficial effects, such as preventing the nausea, vomiting and anorexia associated with HIV infection and treatment, but all pose substantial risks to the human body. This is especially true given our limited knowledge about how cannabinoids are made and work naturally in the body.

Many of the synthetic formulations of cannabinoids are now available in pill form through a prescription written by your physician and filled by your pharmacist. A benefit of the pill form is that the cannabinoid can be administered without the deleterious effects of the ingested smoke, but by the same token, the pills have less rapid onsets of action, and they are relatively devoid of the euphoric effects that are experienced when the cannabinoids are smoked.

A recent and alarming development in the cannabinoid world has been the marketing of products under the brand names of “Spice” and “K2”. Spice was originally marketed as an “incense blend which releases rich aroma” and the blend was reported to contain plant ingredients such as Indian Warrior, Lion’s Tail, Baybean, Blue Lotus, Vanilla, Honey, and others. In addition, it was said that these products were meant “not for human consumption.” It has now been revealed that these products have psychoactive effects that are due to added synthetic cannabinoids.


Cannabinoids have many effects on brain and body functions. Cannabinoids can induce a euphoric effect on mood, they can produce perceptual changes such as causing colors to seem brighter, music to seem brighter, and emotions to seem more poignant and meaningful. In addition, time perception is impaired so that perceived time goes faster than clock time. At high doses, hallucinations may occur. Cannabinoids also impair psychomotor performance. Reaction time, motor coordination, and short-term memory may be impaired. Likewise, driving and piloting skills are severely impaired by cannabis ingestion.

Systemically, cannabinoids can cause dilation of the blood vessels and reflex rapid heart beating. Furthermore, the smoke from herbal cannabis preparations contains bronchial irritants and tumor promoters. Chronic cannabis smoking is associated with bronchitis and emphysema.

Despite all of these negative effects, cannabinoids do have some beneficial effects that are contributing to their increased political and legal acceptance. Cannabinoids are effective at treating nausea and vomiting associated with cancer chemotherapy, loss of appetite, pain, multiple sclerosis, spinal cord injuries, Tourette’s syndrome, epilepsy, glaucoma, Parkinson’s disease and dystonia.


All of these observations lead us to conclude that marijuana is a drug that must be used with caution under the supervision of people trained to maximize its effectiveness and safety.

We have learned how food and drugs can manipulate the brain dopamine system in order to signal that they have “incentive salience” for satisfying our wants. Thus, we understand, that under the lack of the ability our younger and less strong frontal cortexes to control our older and more robust subcortical brain structures, these compounds that provide incentive salience are able to control our ingestive behaviors. In other words, these compounds that have incentive salience are able to control us, and in a way, induce the brain disease of addiction. The best tools we have for coping with these addictions require training of our frontal cortexes.


The Project ALERT curriculum is particularly strong at helping us teach our students appropriate coping skills.

You’ve probably heard of the research involving youngsters who were presented with a marshmallow. They were left in a room alone for period of time and told that if they could endure the period of solitude with the marshmallow without eating the sugary confection, they would be granted two marshmallows at the conclusion of the period of solitude. After following these kids for years after the study, it was found that those youngsters that could abstain from eating the marshmallow during the lonely period would not only get two marshmallow’s at the conclusion of the test period, but would also go on to lead more productive and successful lives by most indices. Subsequent research has indicated that it wasn’t will power that provided these youngsters with the ability to abstain from eating a marshmallow and leading more successful lives, instead it was their ability to cope with the challenge, and even more importantly, the researchers found that the skills to cope can be taught.

Mailing List

Sign-up for The ALERT Educator