Researchers in Brazil are claiming their findings may pave the way to proving CBD compounds could reduce aggressiveness caused by social isolation.
Although early in their research programme, scientists from the University of São Paulo’s Ribeirão Preto Medical School (FMRP-USP) believe the evidence from their current experiments have the potential for treating people who require anti-psychotic or antidepressant drugs to treat aggression related to isolation.
The Brazilians used mice for their experiments, but
anticipate being able to replicate the studies in humans.
Led by Professor Francisco Silveira Guimarães, the
team gave four groups of mice different levels of CBD to assess what effects
the compound would have on mice that were showing signs of aggression following
days of isolation.
As a control level, a fifth set of mice were given
none of the cannabidiol solution.
Members of the fifth group attacked another mouse within
two minutes of it being introduced into their cage. A further 20 to 25 attacks
The group injected with the equivalent of 5mg/kg of
the compound began its attack after four minutes, with half the number of
The next group, which received 15mg/kg were the least aggressive of any of the groups. They attacked the intruder mouse after 11 minutes, with only five follow-up attacks.
Curiously, however, the group receiving the higher
doses – 30mg/kg and 60mg/kg launched their attacks sooner and with more
frequency, leaving the scientists scratching their heads but not surprised.
According to Guimarães, the reduction in effects from
the higher dosage matched the results from previous studies.
“In experiments to investigate its potential as an
antidepressant, for example, higher doses led to lower effects after an initial
gain,” he explained to the journal Progress in Neuro-Psychopharmacology and Biological Psychiatry.
“In our experiment, if we had tested 120mg/kg on a group of mice, we
might not have obtained any inhibition of the resident’s aggressiveness at all.”
far, the researchers have deduced that CBD likely activates
a small number of receptors in the brain that are able to have a calming effect
“CBD decreased c-Fos protein expression – a neuronal activity
marker – in the lateral periaqueductal grey (lPAG) in social-isolated mice
exposed to the resident-intruder test, indicating a potential involvement of
this brain region in the drug effects,” Guimarães added.
“Taken together, our findings suggest that CBD may be
therapeutically useful to treat aggressive behaviours that are usually
associated with psychiatric disorders.”