CBD, short for cannabidiol, is a molecule extracted from cannabis that does not make you high, but has other effects that have attracted the interest of researchers in a variety of medical fields, including epilepsy treatment and psychology.
Aggressive behaviour in humans is more common than one might think. However, the exact neurological causes of aggressiveness are not well known. Thanks to medical research, however, we now know that aggression can be treated with drugs such as antidepressants or antipsychotics.
With nature against aggression
Since older studies have already shown that cannabidiol (CBD) can cause a similar effect to the drugs mentioned above, Brazilian researchers have conducted their own study to investigate whether aggression can be reduced or eliminated by the use of CBD.
The study focused on mice that had experienced rather bleak circumstances. They were isolated for ten days, which meant that they became aggressive and attacked others as soon as they were re-socialized.
To evaluate the effects of CBD, one gave a group of aggressive mice CBD injections in the range of five to 60 mg / kg body weight. Then these angry mice underwent the "Resident Intruder Test". The scientists confronted the aggressive mice with "normal" conspecifics and waited to see if CBD affected the way these isolated mice reacted to contact.
Overall, mice that received any amount of CBD attacked the "intruders" less than mice that did not receive CBD, and mice that received an average dose of 15 to 30 mg/kg spent less time attacking the intruders.
The authors concluded that their results showed a connection between CBD and reduced aggression. When they examined their results in detail, they discovered CBD-related biochemical changes that could explain these findings.
They observed that CBD activated two types of receptors in their mice. One was the 5-HT1A receptor, which is involved in mood control because it binds to serotonin (low serotonin levels are one of many factors underlying clinical depression). The CB1 receptor is part of the body's endocannabinoid system - a network of neurotransmitters and receptors that Lisboa calls a "buffer system" that can modulate stress responses.
"Aggression could cause disruption to serotonin and endocannabinoid mechanisms, CBD could mitigate this by promoting regulation of these systems," Lisboa suggests. "However, we do not know how CB1 and 5-HT1A receptors mitigate aggression."
How does the calming effect of CBD work?
Cannabinoid receptors are produced in the body and are involved in body processes such as appetite, pain, mood and memory. Professor Guimarães said: "We do not yet know how exactly the 5-HT1A and CB1 receptors influence aggressiveness in mice, but the activation mechanisms involved appear to be different in each case. Cannabidiol has been studied in various contexts over the last 20 years, but its effects on aggressive behaviour have only recently been investigated".
Ian Hamilton, a lecturer on mental health and addiction at the University of York, an expert who was not directly involved in the study, commented on the results: "No one has ever conducted such an experiment, but we generally know that CBD has a dampening effect on the brain, especially in psychosis. CBD has a calming effect on people with mental problems. It looks like it has potential to support impulsive control, and this can be seen in many things like autism, depression, anxiety and aggression.