Cannabinoids, Learning, and Memory

Global activation of CB₁ receptors produces actions on hippocampal neurons, which results in interference with short tem memory and consolidation of memories that are currently being processed. However, such CB₁ receptor activation does not impair recall of previously established memories. Evidence suggests that the acute effects of cannabis on memory depend in part on the type of cannabis that is used. THC acts to impair short-term memory and the consolidation of new memories, but CBD protects against the memory impairing effects of THC. There is conflicting human evidence that chronic exposure to cannabis can produce permanent changes in learning and memory processes and/or can modify the human adolescent and adult brain functioning. This evidence is reviewed.