Huntington’s disease is an incurable, hereditary brain disorder. Nerve cells become damaged, causing various parts of the brain to deteriorate. The disease affects movement, behavior and cognition – the affected individuals’ abilities to walk, think, reason and talk are gradually eroded to such a point that they eventually become entirely reliant on other people for their care. Huntington’s disease has a major emotional, mental, social and economic impact on the lives of patients, as well as their families.
Traditionally, most physicians prescribe a number of medications to help control the various emotional and physical symptoms of HD, although these are used to make living easier and don’t actually address the underlying problem at its root. One of the downsides to taking medication for HD and other cognitive disorders is that they commonly have a lot of side effects, such as fatigue, insomnia, appetite and mood changes, etc.
Cannabidiol (CBD) is a major non-psychoactive cannabinoid of marijuana. Based on reports indicating possible efficacy of CBD in dystonic movements, CBD was given to three patients with Huntington’s disease (HD). The patients, aged 30 to 56, had HD of 7 to 12 years’ duration. Their condition has been slowly progressive and unresponsive to prior therapy with neuroleptics. Orally administered CBD was initiated at 300 mg/d and increased 1 week later to 600 mg/d for the next 3 weeks. Mild improvement (5 to 15%) in the choreia movements was documented using the tongue protrusion test and a chorea severity evaluation scale after the first week. Further improvement (20 to 40%) was noticed after the second week of CBD, and this remained stable for the following 2 weeks. Except for transient, mild hypotension, no side effects were recorded, and laboratory tests were normal. Withdrawal of CBD after 48 hours resulted in return of choreic movements to the pre-CBD state.
Researchers from the Ramon y Cajal University Hospital’s Foundation for Biomedical Investigation in Madrid have recently completed the first ever clinical trial to investigate a cannabis extract as a treatment for Huntington’s Disease. The genetic mutation causes damage to striatal and cortical neurons, putting neuroprotective drugs at the forefront of Huntington’s Disease research. Initial research has shown that cannabidiol (CBD), displays neuroprotective effects in mice with similar conditions to the disease. Experimental evidence showed researchers that CBD aid neurons with its antioxidant properties. Though CBD and THC are almost identical molecules, CBD’s arrangement allows it to be a powerful antioxidant that is also safe and tolerable at high doses in humans.
In a later experiment, CBD and THC administered together at equal ratios also caused similar but enhanced neuroprotective effects to CBD alone. The endocannabinoid system is intricately tied to the progression of Huntington’s Disease and researchers have discovered that early on in the disease, cannabinoid receptors disappear massively in striatal neurons.
Increased research on cannabinoid medicine and modulation of the endocannabinoid system in relation to Huntington’s Disease has the potential to not only lead to symptom management for patients, but also to novel therapies which may help to prevent progression, and potentially initiation, of the disease.