What is the role of cannabinoids as an intoxicant and in medical applications today? This was the question addressed by Dieter Braus, MD, psychiatrist and neurologist at Vitos Clinic Rheingau in Eltville, Germany, at the DGIM Congress 2022.
Dampening the Dopamine System
Regardless of the type of substance-dependent addiction — whether alcohol, opiates, nicotine, or cannabinoids — the brain pathway is the same: the dopamine system. This system is also responsible for curiosity, desire, learning, and actions. Various substances lead to increased neurotransmitter release.
The endocannabinoid system acts as a damper on this system. System stabilization is inhibited by the high-affinity binding of delta (9)-trans-tetrahydrocannabinol (THC) to CB1 receptors. The psychotropic component of cannabis naturally accounts for 1%–2% of the active substance. However, this proportion has now increased to 10%–20% as a result of selective breeding. At the same time, the proportion of cannabidiol (CBD), the nonpsychoactive counterpart, has fallen.
In addition to the acute THC effect with a high and pleasant feeling, chronic consumption produces different effects. Retrograde signaling pathways are disrupted, leading to addictive behavior, reduced motivation, and negative emotionality. These chronic effects may even occur after only a few instances of consumption.
Deep brain regions, such as the hippocampus, substantia nigra, amygdala, and hypothalamus, have the greatest densities of CB1 receptors.
