Some recent highlights and curiosities from the amazing world of cannabis science and therapeutics:
- CBD and autism. In his first article of the new year, Raphael Mechoulam and other Israeli scientists look at the “real life experiences of medical cannabis treatment in autism.” Published in Nature, the study found that just under a third of patients report significant improvements and over half report moderate improvements while using CBD-rich oil derived from cannabis (30% CBD, 1-2% THC). The improvements include decreased aggression and agitation, fewer seizures, and better sleep, appetite and ability to concentrate. Around 10-20% of patients stopped taking various medications (mostly antipsychotic and antiepileptic drugs) within 6 months of starting cannabis treatment. One quarter of people experienced some negative side effects like sedation or restlessness, but none were severe. And about one in 5 stopped treatment because it wasn’t effective. Even though there remains a lot to be discovered about how and why CBD can improve the lives of people with autism, it is clear that cannabis can be used safely by this population and should be studied further.
- Cannabis and ADHD. A study in Molecular Psychiatry with tens of thousands of people found an association between ADHD and cannabis use. Their data suggests that ADHD causes later cannabis use, which may support the notion that THC is used to self medicate (although ADHD is associated with heavier use of many drugs). Previous research has found that THC may be effective for some cases that do not respond well to Ritalin.
- Self medicating for endometriosis. Endometriosis is a poorly-understood condition causing severe chronic pain and alterations in a woman’s menstrual cycle. As an understudied disease, treatment is limited. Scientists surveyed over 400 Australian women to see what actions they took to treat their pelvic pain. Cannabis, heat, CBD oil, and dietary changes were rated most effective by women, in that order. Unfortunately, more women used alcohol than cannabis to manage symptoms; self-medicating with alcohol promotes chronic inflammation and led to worsening pain and fatigue in over half of such women. This underscores the importance of not treating cannabis like alcohol in the ongoing saga of legalization. (Note: endometriosis is diagnosed with an invasive surgical procedure, and so many women who likely have endometriosis go undiagnosed. The group that responded to this survey had a confirmed diagnosis.)
- Concussions and alcoholism. Traumatic brain injury (TBI) leads to numerous problems, including alcoholism and suicide. New findings indicate that endocannabinoids aid TBI recovery: When researchers boosted 2-AG levels shortly after injury, rats displayed less anxiety and less interest in alcohol. This is significant since alcoholism is a serious comorbidity of brain injury. The researchers link the protective effect of 2-AG to changes in glutamate transmission in the central amygdala, the part of the brain that processes traumatic and fearful memories. Other preclinical research has demonstrated that endocannabinoids can play a protective role after traumatic brain injuries, like concussion, by ameliorating glutamatergic toxicity.
- Cannabinoid crystals. Across political boundaries, a group of scientists from Russia, China, and the USA crystallized the CB2 cannabinoid receptor. This is a major achievement that will deepen our understanding of how CB2 works at a chemical level, even though X-rays of the crystal don’t provide a perfect representation of CB2 as it exists in the body. Many of these scientists were also involved in crystallizing the other main cannabinoid receptor, CB1, in 2016. These developments are also a major help to those trying to design new drugs targeting cannabinoid receptors. To get a better sense of what “understanding” the chemical structure of the CB2 entails, see these articles on A lipid pathway for ligand binding is necessary for a cannabinoid G protein-coupled receptor and Structure-kinetic relationship studies of cannabinoid CB2 receptor agonists reveal substituent-specific lipophilic effects on residence time.