“This article reviews the neurocognitive advantages and drawbacks of cannabinoid substances, and discusses the possible physiological mechanisms that underlie their dual activity. The article further reviews the neurocognitive effects of ultra-low doses of ∆9-tetrahydrocannabinol (THC; 3-4 orders of magnitude lower than the conventional doses) in mice, and proposes such low doses of THC as a possible remedy for various brain injuries and for the treatment of age-related cognitive decline.”

https://www.ncbi.nlm.nih.gov/pubmed/30864864

https://www.tandfonline.com/doi/abs/10.1080/00952990.2019.1578366?journalCode=iada20