A new study with mice shows that THC, one of the active ingredients in marijuana, was able to improve the brains of elderly mice to the level that their brains resembled those of rodents who were only two months old. THC is the substance that causes people to get “high”. However, the amount given to the mice was too small to induce that effect. The researchers tested the cognitive performance of the mice through tasks such as how well they were able to orient themselves and how well they were able to recognize other mice. Next for the research team is finding out whether or not THC has the same effect in humans. If so, treatment with the compound could help combat diseases that impair our cognition as we age, such as dementia.