New research has shed light on a mechanism for how CBD affects the principal cannabinoid receptor in the brain. The discovery gives further insight into using CBD to treat conditions like epilepsy, depression, and other neurological disorders, and also helps explain the different psychoactive effects produced by cannabis that has some CBD, compared to cannabis with only THC.
CBD has received a lot of mainstream attention in the past few years for its ability to treat refractory epilepsy in children, but CBD has many medical applications. Some dispensaries offer medicinal products with varying ratios of CBD and THC, with the idea being that CBD not only has a therapeutic effect on the body, but also tones down some of psychological effects of THC. The new discovery shows how CBD can act as a sort of antidote for some of the potentially discomforting psychological effects of extremely high doses of THC.
This latest research from Halifax, Canada has found that CBD is a negative allosteric modulator of the cannabinoid receptor 1 (CB1), the same receptor responsible for THC’s psychoactive high. Simply put, CBD is able to bind to the CB1 at a different spot on the receptor than THC does. When THC binds to a CB1 receptor on the outside of a neuron, the receptor creates certain signals on the inside of the cell. If CBD binds to the CB1 receptor at the same time as THC, the neuron gets a lesser signal. The two substances in combination act synergistically at the cannabinoid receptor creating a an effect that is distinct from that of THC alone.
Scientists already suspected that CBD must act on the CB1 in a way that infringes on THC’s action on CB1, as shown in previous work. In addition to its interaction with the CB1 receptor, CBD's other medicinal effects stem from completely separate pathways, such as the cannabinoid receptor 2 (CB2), mu- and delta- opioid receptors, etc. Taken on its own, CBD has sedative, anxiolytic (anti-anxiety) and antideppressant effects on the brain, but does not create any overtly psychoactive high like THC.
This new discovery represents another important step forward into understanding the effects of cannabis on the brain. Further research like this will help doctors and caregivers chose strains to prescribe to patients with different needs.