Barriers to Research
28. Aran A, Harel M, Cassuto H, et al. Cannabinoid treatment for autism: a proof-of-concept randomized trial. Mol Autism. 2021;12(1):6.
Even NIDA has acknowledged federal limitations on cannabis research. In 2015, Nora Volkow, MD, NIDA’s director, spoke before the US Senate Caucus on International Narcotics Control. 36 She acknowledged application barriers to research and the lack of well-controlled clinical trials. She also noted CBD’s potentially positive effect on a variety of symptoms, including children with drug-resistant epilepsy.
There are other clinical trials currently underway that are worth following to see what they discover. Children’s Hospital of Philadelphia recently completed an observational study in collaboration with Zelda Therapeutics, an Australian biopharmaceutical company, to track children with autism who are independently using medical cannabis to address symptoms. Results have not been published yet. 30 Another ongoing phase 2, 12-week double-blind, randomized, placebo-controlled trial study, funded by the US Department of Defense, is studying how behavior in children with autism might be affected by cannabidivarin, a nonpsychoactive phytocannabinoid, which is a safer alternative to CBD. 31
Approval to conduct cannabis research comes from both the FDA and the DEA. The process takes more than a year, with some researchers waiting even longer. Strict protocols govern how cannabis is stored, requiring limited access in an alarm-controlled, locked container physically attached to a floor or wall, according to the UCSF report. 35 These obstacles create a catch-22 for medical marijuana research, according to the State of Cannabis Research Legislation in 2020, a report led by Ali Zarrabi, MD, associate director of outpatient support and palliative care at Emory University. 37
How might cannabis help autistic people?
Epidiolex’s success has spurred many parents to try marijuana and cannabis extracts for seizures, behavioral issues and other autism-related traits in their children, but experts warn that these drugs remain largely untested for such purposes. Some studies on cannabinoids have shown promising results in animal models and in early-stage clinical trials, but this research does not yet support their widespread use.
Some research has shown that recreational marijuana use beginning in one’s teenage years can have negative long-term effects on cognition 11 . But experts note that the dosages used for medical purposes are often quite lower than those used in a recreational context.
Cannabis’ active ingredients are thought to exert their effects by binding to proteins called cannabinoid receptors in the brain: THC activates the CB1 and CB2 receptors, whereas CBD seems to block them 2 .
Are there any cannabis-derived drugs approved to treat autism or related conditions?
To date, the U.S. Food and Drug Administration has approved only one cannabis-derived drug: Epidiolex. It is a liquid cannabis extract containing purified CBD that can decrease seizures in people with Dravet syndrome or Lennox-Gastaut syndrome — severe forms of epilepsy that are sometimes accompanied by autism — and in those with tuberous sclerosis complex. It is available only by prescription, and only for these three conditions.
Both types of cannabinoid receptors are located in neurons in the brain and throughout the body. The brain contains more CB1 than CB2 receptors, and the activation of each receptor type affects a range of ion channels and proteins involved in cell signaling 3 . The ultimate effects of cannabinoid receptor activation depend on which body system they belong to. For instance, the activation of CB1 receptors in the brain can either increase or decrease neuron excitability, depending on which kind of neuron a cannabinoid binds to; activation of CB2 receptors in the digestive system can decrease inflammation 4,5 .