WHEC News in Rochester, New York, is reporting that more adults are turning to medical marijuana to treat their child's autism. The parents claim that it is a "miracle drug" after they have witnessed its results in the behavior of their children, such as lower aggression, reduce self-harm and improve overall behavior. New York does allow doctors to prescribe medical marijuana but only if it passes a strict list of qualifying conditions. Autism is not on the list. Interestingly, seven other states include autism spectrum disorders (ASDs) to be treated with medical marijuana, so why is New York holding out?
Well, there is only anecdotal evidence that marijuana can help children with autism. In science (as it should be in governmental policy) anecdotal evidence is, well, not really considered evidence. So, what do the actual data say? A review of the literature published in the Journal of Developmental & Behavioral Pediatrics in 2015 highlights some of the real evidence we have on the science of marijuana and autism. According to Drs. Scott E Hadland, M.D. and John Knight, M.D., of Harvard Medical School, most of our knowledge about the effects of marijuana on autism come from animal-based models. These reports hit the news (e.g. High Times and The Huffington Post) and many parents, with such few options left for their children, often take that preclinical evidence and run with it.
One could easily forgive a parent without many choices, faced with a bombardment of medical marijuana miracle claims in the past five or so years, to give medical marijuana a try. However, a concerned scientist with an eye on the long game could not in good conscience recommend a medical treatment based only on the results of tests with mice. The authors of the literature review said as much when they noted that there was "a dearth of scientific evidence supporting a role for cannabis in these [behavioral] conditions".
In fact, there is a lot more evidence, from both human and animal studies, to suggest that marijuana use as a child or adolescent can interfere with brain development and pose behavioral and emotional problems in adulthood. Another literature review published in The Lancet in 2009 listed that chronic marijuana use by children and adolescents could "adversely affect mental health in young adults...[with] an increased risk of psychotic symptoms and disorders." Another review, published in the New England Medical Journal in 2014 by Dr. Nora Volkow, Ph.D., the head of the National Institute on Drug Abuse, describes how chronic marijuana use in adolescents is linked to deficits in neuronal connections as well as mood disorders in adulthood. Furthermore, adolescent use has been shown to "sensitize" the brain's "reward circuit" to make it potentially more likely to become addicted to marijuana or other drugs.
Is there any human (or animal) evidence to suggest that medical marijuana could be beneficial to a minor with ASD? The only definitive link has been through the prevalence of epilepsy in the population of people with ASD. It just so happens that one of the most robust findings of a marijuana health benefit comes from peer-reviewed studies on marijuana and epilepsy. In fact, the Federal Food and Drug Administration (FDA) has even recently approved cannabidiol (CBD)-based medication for epilepsy treatment in children.
In terms of ASD more generally, however, studies have just started to get underway. As of the spring of 2018, researchers from New York are preparing to launch a major study on whether various compounds from marijuana can treat autism. These studies (which you could sign up for at ClinicalTrials.gov) they will be running clinical trials on adolescents and children as young as five years old. Unfortunately, this study has not yet started and is only one of two studies (according to ClinicalTrials.org) that are directly searching for a marijuana-based treatment for autism. Until data from those studies start to come in, we are left with the anecdotal evidence. See the video below and you be the judge.