WHO report: CBD has a "good safety profile" and "may be a useful treatment."
The World Health Organization (WHO) in a November 2017 report concluded that "CBD is generally well tolerated with a good safety profile. Reported adverse effects may be as a result of drug interactions between CBD and patients' existing medications. Several countries have modified their national controls to accommodate CBD as a medicinal product...CBD has been demonstrated as an effective treatment of epilepsy in several clinical trials...There is also preliminary evidence that CBD may be a useful treatment for a number of other medical conditions."
A Q&A page on the WHO website clarifies that "in its pure state, cannabidiol does not appear to have abuse potential or cause harm...A further review of extracts or preparations containing almost exclusively CBD will take place in June 2018." We are surmising that this may be a review of CBD (or CBD oil) from hemp or high CBD/low THC preparations from marijuana.
In the section of the WHO report "Overview of diseases for which CBD may have therapeutic benefits", concussions or traumatic brain injuries are not listed, but the neuroprotectant effects of CBD are listed in the sections on Alzheimer's Disease and Inflammatory Diseases.
"Alzheimer's disease: Antiinflammatory, antioxidant, antiapoptotic in in vitro and in vivo models of AB-evoked neuroinflammatory and neurodegenerative responses."
Concussion symptoms such as pain and anxiety are referenced in the "Overview of diseases for which CBD may have therapeutic benefits."
"Anxiety: Reduction of muscular tension, restlessness, fatigue, problems in concentration, improvement of social interactions in rodent models of anxiety and stress, reduced social anxiety in patients."