Cannabidiol (CBD) reduced lasting memory impairments caused by stress during adolescence and helped protect important brain cells, according to a new study published today.
The study, published October 17 in Progress in Neuro-Psychopharmacology and Biological Psychiatry, was conducted by researchers including Thaís Santos Almeida Lima, Flávia Alves Verza, Livea Dornela Godoy, Francisco S. Guimarães and Felipe V. Gomes. It examined whether CBD treatment following stressful experiences during adolescence could prevent neurological and behavioral problems that persist into adulthood.
Researchers exposed adolescent male mice to repeated stress over 10 days, then administered CBD at a dose of 30 milligrams per kilogram of body weight for another 10 days. The animals subsequently underwent a 15-day period without CBD before researchers began evaluating their behavior and cognitive performance as adults.
Mice exposed to adolescent stress demonstrated significant impairments in social recognition memory, including difficulty distinguishing familiar animals from unfamiliar ones. They also performed worse in tests measuring their ability to recognize previously encountered objects.
CBD treatment significantly reduced both types of memory impairment, with treated mice demonstrating better recognition of familiar objects and other animals compared to stressed mice that did not receive CBD.
Researchers also identified neurological changes that may explain the improvements. Adolescent stress reduced populations of parvalbumin-positive interneurons, specialized brain cells involved in regulating communication between neurons, along with protective structures surrounding those cells known as perineuronal nets.
These changes were observed in the medial prefrontal cortex and ventral hippocampus, two brain regions involved in memory, emotional regulation and cognitive processing. CBD treatment reduced the stress-related loss of these cells and their surrounding structures, suggesting that the cannabinoid helped preserve neural networks important for healthy brain function.
The benefits were particularly notable because they remained evident in adulthood, well after CBD administration had ended.
Not all behavioral measures were affected. Adolescent stress did not produce detectable changes in anxiety-like behavior or general sociability in the tests used, and CBD did not significantly alter those outcomes.
The researchers concluded that CBD may help counteract long-lasting cognitive and cellular changes associated with adolescent stress, particularly those involving neural circuits responsible for memory and information processing.
The findings provide additional preclinical evidence of CBD’s potential neuroprotective properties and suggest that treatment following stressful experiences may help reduce some of their lasting neurological consequences.
