Previous studies have shown that periodic use of marijuana can cause memory loss and impair learning but a new study shows that the drug could have some benefits when used regularly in a highly potent form. It seems as if marijuana could be good for our brain.

Chronic use of marijuana caused nerve cells to regenerate in rats' hippocampuses, part of the brain responsible for learning and memory. If the same thing would happen in people’s brains, it could help us improve learning and memory abilities.

The scientists also noticed that cannabinoids kept in check depression and anxiety that appear when few brain cells are made.

Rats were injected with a synthetic substance called HU-210 when showed such performance. HU-210 is similar but 100 times as potent as THC, the compound responsible for giving marijuana users a high. It is still not known if pot would make the same effect as it is not so pure.
Another problem for not being able to tell for sure is that there's a big gap between rats and humans.

These findings have woken is a lot of interest and more research will be done to come to the right conclusions.