The relationship between cannabis & anxiety is complex and confounding. While some people enjoy anxiety relief from cannabis use, other people can accidentally induce symptoms of panic, particularly from products containing THC. While these personal differences are mostly attributed to unique physiology, it’s also true that many cannabinoids are known for having a biphasic effect. This means that the drug will produce different effects at different doses. While lower doses of THC may induce physical relaxation and suppression of anxiety-like symptoms, higher doses can actually do the opposite. 

Interestingly, it's likely that the specific concentrations of GABA and glutamate in the central nervous system have the most significant effects on the excitatory properties of cannabis, and THC. THC interacts, primarily, with CB1 receptors densely located in the central nervous system, where it modulates the concentration of glutamate and GABA. Glutamate is one of the most proliferate neurotransmitters in the brain, responsible for having an excitatory effect, while GABA acts in the opposite manner, and the two work in tandem to promote balance. 

We’ll explore research on the effects of specific cannabinoids below, before touching on the entourage effect and the potential influence of various terpenes in conjunction with cannabinoids.

THC

The biphasic quality of THC is quite famous, and most people who are familiar with recreational cannabis have experienced both anxiety (often at higher doses), and anxiety suppression (often at lower doses). That being said, there is increasingly extensive research on the potential anxiety relieving effects of THC. 

THC modulates CB1 receptors, which constitute the majority of the endocannabinoid system. CB1 receptors are located densely throughout the amygdala and central nervous system, sending signals that interact with GABA and glutamate neurotransmitters, which, broadly, oversee the primary excitatory effects of anxiety in a neurological sense. Therefore, the role that THC can have in modulating or attenuating anxiety can vary widely depending on individual neurochemistry and a medley of other factors. For this reason, it can be difficult for cannabis professionals to guide clients on dosing accurately. Generally, conventional wisdom is to start with the lowest possible dose, and gradually work upward. 

CBD

Cannabidiol, the second most prevalent cannabinoid in cannabis, offers more subtle but similarly effective anxiety suppression to THC. While some prefer CBD on it’s own because of the non-psychoactive relaxation it provides, others mix THC and CBD, in various ratios, because the combination can actually have an overall combined greater anxiety relieving effect. 

The efficacy of CBD in mediating anxiety-type symptoms tends to follow a bell-shaped curve in animal studies. This means extremely low doses and extremely high doses are less effective at anxiety-reduction, while moderate doses (moderate being subjectively defined with a wide range of possible definitions) offer the most anxiolytic effect. 

CBN

CBN is a trace cannabinoid that is quickly developing a reputation as the “sleepy” or “sedative” cannabinoid. The pharmacological mechanism of action of this rare cannabinoid is only beginning to be understood, but anecdotal reports suggest that CBN is efficacious for sleep because of the anxiolytic-type effects this cannabinoid can induce when taken in significant quantities. The synergistic interactions between CBN and other cannabinoids are largely unknown, but it can be postulated that the anxiolytic qualities of CBD and low-dose THC may accompany, or even expand upon, those of CBN. 

The Entourage Effect

The Entourage Effect describes the amalgamation of pharmacological effects of various constituents within the cannabis plant, which theoretically provide a better overall effect when compared to the effects of isolated compounds acting alone. Following this idea, many people find the combination of THC and CBD to be the most effective for combatting anxiety related symptoms. Contributing to the entourage effect are not only cannabinoids, but also terpenes. Terpenes are the aromatic compounds in the cannabis plant, which are responsible for providing cannabis with its unique scent profile. There are over 100 different terpenes that can be present in a single cannabis cultivar, and each of these terpenes can have unique therapeutic and pharmacological properties. Two of the most famous anxiolytic terpenes are linalool, shared between cannabis and lavender, and myrcene, shared between cannabis and mangos. These, and several other stress-relieving terpenes work in conjunction with cannabinoids like THC, CBD, and CBN, the result of which seems to offer the most promising and reliable anxiety suppression known to cannabis medicine to date. 

Other theories and final remarks 

Certain over-the-counter supplements have unique effects on the same excitatory neurotransmitters affected by cannabis. L-theanine is an amino acid found in green tea that is regarded as a nootropic for its ability to improve focus and relieve anxiety. It does this by acting to reduce the amount of glutamate in the brain, which, in theory, could actively modulate the effects of THC (and other cannabinoids) on mood and anxiety. 

Though cannabis science remains in its infancy, we’re beginning to understand much more about the complex effects of cannabis on anxiety. The unique idiosyncrasies that characterize this mysterious plant will surely continue to unfold with time.