It has long been argued that persistent abuse of cannabis can lead to mental health issues.  One of the standard arguments supporting prohibition of the last 8 decades, and one which cannabis advocates have long argued against, since many neurological health issues are now being treated with cannabis.  Thanks to a recent study, we may now have elucidation on the topic.  And the key is CBD!

In a recent clinical study, CBD repaired negative effects of regular cannabis use on a certain brain region In an open study with 18 regular cannabis users, who took 200 mg of CBD daily for about 10 weeks, the volume of certain areas in the hippocampus of the brain, was increased. Heavy cannabis use may have a negative effect on these areas.

The hypothesis: Chronic cannabis use is associated with neuroanatomical alterations in the hippocampus. While adverse impacts of cannabis use are generally attributed to Δ9-tetrahydrocannabinol, emerging naturalistic evidence suggests cannabidiol (CBD) is neuroprotective and may ameliorate brain harms associated with cannabis use, including protection from hippocampal volume loss.

Materials and Methods: Eighteen regular cannabis users participated in an ∼10-week open-label pragmatic trial involving daily oral administration of 200 mg CBD, with no change to their ongoing cannabis use requested

Conclusions: Our findings suggest a restorative effect of CBD on the subicular and CA1 subfields in current cannabis users, especially those with greater lifetime exposure to cannabis

(Beale C, et al. Cannabis Cannabinoid Res. 2018;3(1):94-107.)