Many studies have shown that cannabis treatment carries only minor side effects such as sedation or restlessness, but these studies have not looked at long-term side effects. Researchers still don’t have a solid grasp on how the active ingredients in marijuana actually affect the brain, nor do they know how these compounds might impact a child or teenager’s developing brain or interact with other medications.
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.
Complicating the picture, CBD alone may not be sufficient for cannabis’ therapeutic effects. A 20-to-1 ratio of CBD to THC relieves aggressive outbursts in autistic children, a 2018 study suggests 8 . This same ratio of compounds significantly improved quality of life for some children and teenagers with autism in a 2019 study 9 . Specifically, researchers observed significantly fewer seizures, tics, depression, restlessness and outbursts. Most participants reported improvements, and about 25 percent of participants experienced side effects such as restlessness.
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.
In many European countries, as well as in Australia, Canada, Israel and Jamaica, medical cannabis is legal, with specific laws varying from country to country.
Under U.S. federal law, CBD products manufactured from industrial hemp are legal as long as they contain no more than 0.3 percent THC. And in some states, CBD oil is permitted to contain up to 5 percent THC.
What is medical marijuana?
Medical marijuana generally refers to any product derived from cannabis plants — including dried flowers, resins and oils — that has been recommended by a doctor. It may be consumed directly or infused into an array of foods, lozenges and candies. These products have become popular among autistic people and their families for treating a broad swath of conditions, including insomnia, epilepsy and chronic pain.
There is no established pharmacological treatment for the core symptoms of autism spectrum disorder (ASD), persistent deficits in social communication, and repetitive, restrictive patterns of behavior ; the efficacy and tolerability of pharmacotherapies addressing comorbid disruptive behaviors are relatively low .
Zamberletti E, Gabaglio M, Parolaro D. The endocannabinoid system and autism spectrum disorders: insights from animal models. Int J Mol Sci. 2017;18(9):1916.
These preclinical data and case-series, reporting treatment with artisanal CBD-rich, cannabis strains [22,23,24,25,26] have triggered widespread use of various cannabis strains in children with ASD, despite a lack of controlled studies. Furthermore, the cannabis plant contains a wide range of minor cannabinoids, terpenes, and flavonoids which differ by strain. These components have also been reported to impact human behaviour [27, 28]. Various combinations of these components have been proposed to have a synergistic pharmacological effect (‘the entourage effect’) . Whether presumed effects of cannabis in ASD should be attributed to CBD or THC, or whether minor cannabinoids, terpenes, and flavonoids also contribute therapeutically remains unclear. Accordingly, we performed a proof-of-concept, placebo-controlled trial of whole-plant extract and pure cannabinoids in children and adolescents with ASD. We hypothesized that whole-plant extract, per the entourage effect, would be more effective than placebo for disruptive behaviors; assessing this hypothesis was our primary objective. A secondary objective was to assess the efficacy of pure cannabinoids which are more standardized and repeatable than whole-plant extracts and hence more suitable for pharmacotherapy.
Salzman C, Kochansky GE, Van Der Kolk BA, Shader RI. The effect of marijuana on small group process. Am J Drug Alcohol Abuse. 1977;4(2):251–5.
There were no treatment-related severe or serious AEs. Six participants had an unrelated serious event (Additional file 1: Table S1). Overall, mild AEs were not significantly more frequent during cannabinoid treatment (mild AEs were reported 383, 388, and 353 times, in 89, 79, and 78 participants during treatment with whole-plant extract, pure cannabinoids, and placebo, respectively). Moderate AEs were reported 80, 78, and 57 times, in 44, 45, and 26 participants during treatment with whole-plant extract, pure cannabinoids, and placebo, respectively. AEs that were more common during cannabinoid treatment are presented in Table 3. The full list of adverse events and correlations with age, sex, treatment dose, and concomitant medications appears in Additional file 1: Table S2.