Studies present evidence: Diminished gray matter in the hippocampus region of cannabis users. Conclusion: Protective effects of cannabidiol (CBD)

Study Author(s): Demirakca, Traute;Sartorius, Alexander;Ende, Gabriele;Meyer, Nadja;Welzel, Helga;Skopp, Gisela;Mann, Karl;Hermann, Derik; Institution: Department of Neuroimaging, Central Institute of Mental Health, J 5, 68159 Mannheim, Germany.


New research indicates that cannabinoids potentially hold the key to effectively treating neurogenerative diseases such as Alzheimers Disease. Undertaken by neurologists Veronica Campbell and Steven Fagan of the University of Dublin,  they explained how (cannabinoids), which target the endocannabinoid system specifically, are the basis for treating neurodegenerative diseases with success. The treatment has been evaluated and believed to have very minimal side effects.
Neurodegenerative disease as it is described is a loss of structure or function of the neurones which unfortunately worsens progressively, the result of which equals death of the neurones. A large number of neurodegenerative diseases including Parkinsons Disease, Huntington’s and Alzheimers occur due to this process.

When asked to elaborate on how neurodegeneration is linked to the ageing process, Fagan explained the connection between a person’s age contrasting it with their brains, since the brain is also believed to experience ageing over time. When a brain is aged, it is more susceptible to an acquisition of disease. Fagan explains that as there becomes a larger ageing population with each new year, more neurodegenerative disorders will be diagnosed alongside the rising senior population.

Ageing naturally leads to changes in the neural chemistry. It is expected for the aged to have experienced a destruction of brain cells over time.  “Current therapies focus on treatment of the symptoms and attempt to delay the progression of these diseases, but there is currently no cure,” Fagan explains. The possibilities of this new treatment need to come to the full realisation of the medical industry before one can determine whether it can be considered a potential cure for neurodegenerative disease in the future.

Fagan’s and Campbell’s research, which builds upon earlier studies by Campbell on Alzheimer’s disease, has been published in the British Journal of Pharmacology. The study shows that such brain- and age-related conditions can benefit from “the modulation of the endogenous cannabinoid system.”

The researchers examined several brains obtained from deceased Alzheimer’s patients to make this determination. These examinations were also made using animals, showing where alterations in components of the cannabinoid system occur. Such a study strongly suggests that the cannabinoid system either contributes to or is altered by, the pathophysiology of Alzheimer’s disease.

From this, an important therapeutic target is identified because alterations in the endocannabinoid system have been seen in Alzheimer’s patients as well as those with Parkinson’s and Huntington’s diseases.

Thus, for further study, the neurologists reviewed the “pharmacological manipulation of the endogenous cannabinoid system, as well as the application of phytocannabinoids and synthetic cannabinoids.”

How the endocannabinoid can be “manipulated” or modulated to act against the neurodegenerative diseases is through activation by the cannabinoid THC. THC, or tetrahydrocannabinol, is the major psychoactive component of marijuana in the cannabis plant.

Cannabinoids affect cannabinoid receptors, such as receptor CB1, which are located in the brain and the central nervous system. The activation can help to regulate aspects of the brain’s inflammatory response, including halting the release of pro-inflammatory chemicals. These receptors are targets for the phytocannabinoids isolated from the cannabis plant (THC) as well as synthetic preparations.

Specifically, Fagan said that the research group has been looking at dronabinol, a chemical derived from THC (synthesised THC is typically referred to as dronabinol) that stimulates the CB1 receptor.

The research team used dronabinol in a pilot study with Alzheimer’s patients in whom it improved nocturnal motor activity and reduced agitation and aggression, without undesired side effects. From the study, the key aspect appeared to be “the anti-inflammatory and antioxidant properties” of the chemical. This is in keeping with the one factor that links the different neurodegenerative diseases together: neuroinflammation. Fagan surmises that the research “highlights the beneficial effects of cannabinoid treatment.”

The conclusion is in keeping with earlier studies, such as one undertaken at the University College London, that have shown that inflammation and the endocannabinoid system have been linked to another neurodegenerative disease: multiple sclerosis. Also, some earlier trials have shown that THC could prevent the loss of dopamine neurones in animal models of Parkinson’s disease.

The Irish research is substantial evidence because, hitherto, there were no known treatments that can slow down the progression of brain-associated disorders. British and Irish research is prohibitive about the use of marijuana in human trials. Nonetheless, Fagan is “not averse to tests which look at the use of cannabis and its active compounds like THC, in human trials.”

With the beneficial effects of THC highlighted, how do the elderly feel about taking medical marijuana or derivatives? Discussing this topic with some residents at a day centre for pensioners in a suburb of north London in the U.K., the reactions were positive.

One woman, Patricia Howe, said: “If I can take something to keep my faculties in check, then it sounds like a good thing.” Asked about the difference between a synthetic pill and smoking medical marijuana, she added: “I’ve smoked pot in the past; it did me no harm. If it helped, I’d be willing to try it again.”

A similar reaction was given by Kirsty Froome when asked about a pill: “It sounds like something we should take.” However, in response to the question of inhaling medical marijuana, she said: “I don’t smoke, but I’d be happy to pop a pill – I take enough of them for my other ailments.”

With the idea appearing favourable to the elderly population and with a growing body of research providing increased understanding of the physiological role of endocannabinoids, a therapeutic opportunity seems to be expanding the use of medical cannabis to address several different types of neurological diseases.