Many have been asking: Does Marijuana Kill Brain Cells?
The belief among many communities that marijuana use kills brain cells and lowers the IQ of an individual came primarily from a study conducted in New Zealand. The study concluded that chronic (no pun intended) users of marijuana who had begun smoking prior to the age of 18, would have an 8 point IQ drop by the age of 38 (drugpolicy.org). Anti-marijuana websites still use this research conducted in this study as a strongpoint against the use of medical marijuana.
The fact is though, that only 3.8% of those participating in the study showed any decline in brain function and the group did not constitute the average marijuana user. The evidence collected did not prove, or even reasonably suggest that the brain function of marajuana users is diminished. The socio-economic factors related those participating in the study, along with the controversy surrounding IQ measurement testing may play a bigger role in mental acuity than the use of marijuana itself.
The structure of THC is similar to a naturally occurring chemical in the brain called anandamide. Because of the similar structure, the brain recognizes THC and allows it to alter brain function (drugabuse.gov). Specifically, the ingestion of THC interacts with cannabinoid receptors in the brain. Two types of cannabinoid receptors have been discovered, the CB1 and the CB2 (news-medical.net).
The receptors known as CB1 are primarily found in the spinal cord and the nerve cells of the brain, but are found in other organs and white blood cells as well. Because CB1 receptors are found in the hippocampus and cerebellum, the introduction of THC will affect the functions relating to the memory process, motor control, and pain regulation. The presence of CB1 in the spinal column is low which may be the reason there is not depressed respiration with THC use.
Cells that influence the immune system have a higher level of CB2 receptors than CB1 receptors. The CB2 receptors have been the source of increased study in the treatment of inflammation and cancers with THC. The CB2 receptors do not produce the effects on the psyche when mixed with THC (news-medical.net). There is also no apparent impact on blood circulation with the CB2 receptors and since these receptors are abundant in white blood cells, it may be possible to hone the THC delivery system to only impact these cells.
According to the National Institute of Health, “marijuana can cause problems with memory, learning, and behavior… It is more likely to happen if they use marijuana every day or started using it when they were teenagers (nlm.nih.gov).” There is no conclusive research which shows that smoking weed does permanent damage to mental processes or that the effects of weed will kill brain cells.
All of the marijuana facts are still being collected. Because studies must take place over decades, with test subjects who keep a consistent level of smoking weed over the course of the study, the information needed to make a sufficient hypothesis are still years away. In the meantime, does marijuana kill brain cells? Look at yourself and those you know who smoke weed everyday and decide for yourself.