Sativa and Indica are Dead. Long Live the Chemovar
Sativa and indica are not accurate ways to describe the medicinal effects of cannabis.
Patients who use medical cannabis tend to stick to “sativa” or “indica,” claiming that one works better than the other. The classic example is the belief that sativa heightens anxiety, whereas indica does not. But is it really that simple? Do ALL sativas increase anxiety or is something else going on?
In a recent survey conducted in California, preferences for indica or sativa were noted among 95 participants, depending on the medical condition they were treating. The participants preferred indica at a statistically significant level for pain management, sleep, non-migraine headaches, glaucoma, neuropathy, spasticity, seizures and joint pain, while they favored sativa for euphoria and enhancement of energy.
The difference in the effects caused by sativa and indica arise from the differences in their chemical compositions. It is known that over 400 chemical entities are present in cannabis plants including cannabinoids, terpenes, and non-cannabinoids. These can act alone, or in concert with each other, a topic that has been insufficiently explored at this point of the medical cannabis research.
It has been suggested that the higher prevalence of ∆9 – tetrahydrocannabinol (THC) in sativa, which is the psychoactive component, may be the reason why this variety induces anxiety. Cannabidiol (CBD), on the other hand, is more abundant (relative to THC) in indica and could potentially explain how indica strains act to relieve anxiety.
So, does it follow that the more THC there is in the plant, the more likely it is to cause psychoactively adverse events, such as increased anxiety? Unfortunately, it isn’t that straightforward. As mentioned, the complicated interactions between the different chemical entities create the specific effects of each plant variety. In fact, a rising number of researchers and medical practitioners are arguing that the terms “sativa” and “indica” are used erroneously to label the different plant varieties. They argue that “chemovar” is a much more appropriate designation for all cannabis plants. And then we would get specific from there.
This is how things work once the cannabinoids get inside your body: THC, as the main psychoactive component of cannabis, binds to receptors CB1 and CB2. These already exist as part of the endocannabinoid system in a variety of human tissues. Binding of THC to these receptors exerts a myriad of physiological effects affecting emotions, pain, digestion, to name few.
CBD on the other hand, has no binding affinity for these receptors. Rather, it exerts its effects by being a negative allosteric modulator of CB1. This means that without binding to the receptor, CBD is capable of preventing other things to bind that normally have the affinity for CB1 (such as THC). Simply put, it prevents THC from binding.
If these two cannabinoids are the main players, then it would be expected that the higher ratio of THC:CBD in sativa would always be associated with more pronounced psychoactive effects, some of which may be adverse (i.e. anxiety/paranoia). Conversely, a chemovar proportionately higher in CBD, such as indica, would be expected to be more relaxing. This relaxing effect would be true even if the two chemovars had the same amount of THC because it is the CBD content that is moderating the psychoactive effects.
This is not the case. The situation is further complicated when we take into account that the effects of the other non-cannabinoids that are present in chemovars. These include terpenes: myrcene (with its analgesic, sedating properties), limonene (which is an antidepressant and immune-stimulating), pinene (acting as acetylcholinesterase inhibitor alleviating short-term memory impairment from THC) and the sesquiterpenoid beta-caryophyllene (which acts as anti-inflammatory analgesic and selective full agonist at the CB2 receptor site). It becomes apparent that sativa and indica differ by a lot of factors, over 400 to be exact, most of which have not even been characterized yet. And that an indica can behave like a sativa and the converse. This would be based on the interactions of all of these other chemicals.
The relative proportions of all the chemical components will dictate the composite pharmacological and psychoactive effects. Needless to say, such information will be invaluable to patients and medical practitioners as they approach treatment of various conditions. Currently, sophisticated analytical methods are being used to produce the exact chemical profiles of chemovars, and the future is bright for selecting chemovars that specifically match your medical need.