Lots of information to digest. You last comment has been well studied. Regular cannabis use in the teen years has been shown to cause a serious increase in psychological problems noticeable in the mid 20's. It is also shown to cause long term problems with memory such that the ability to retain information is negatively effected. This appears to be a permanent effect.

When the term neuro-protective is used, one must consider it different meanings. Some substances are neuro-protective at a cellular level. Progesterone is on such substance. Others act be reducing inflammation. Alcohol and CBD appear to be valuable for their anti-inflammatory value. Although alcohol has been know to reduce brain injury if it is on-board at the time of the injury, it is well known that alcohol does not enhance healing and should not be on-board during the healing process.

As the CBD study says, more research is needed to define what the value of CBD is to injured brain cells. The study used subjects with more severe TBI than those experienced by concussion subjects. Unless the subject was driving a car, it would not be a normal procedure to do a tox screen on a concussion patient at the ER / A&E. This limits the subjects in the studied group.

It is odd that the study looked for a positive THC in the tox screen when the other research suggests that it is the CBD that has the anti-inflammatory effect. It does not look for other co-factors than may have played a part.

The article about CBD use with intractable epilepsy has no bearing on the value of CBD in TBI recovery unless the TBI subject is suffering from intractable seizures. Resolving intractable seizures after a TBI would only be a small part of the recovery needed. Those with TBI caused intractable seizures have a low survival rate due to the totality of the injury.

The comment that Cannabis was a life saver in the poster's injury is without basis. It does not sound like ASH's injury was ever a life threatening situation.