Cannabis – including its key compounds cannabidiol (CBD) and tetrahydrocannabinol (THC) – is gaining attention as a potential therapy for various neurological and developmental conditions. People diagnosed with autism and other neurological disorders like epilepsy, ADHD, anxiety, and Parkinson’s disease are exploring cannabis-based products to manage challenging symptoms. This article reviews the science, potential therapeutic benefits, and drawbacks of medical cannabis use across these conditions, highlighting differences between CBD and THC, variations in response between children and adults, and important legal and ethical considerations.
Cannabis: CBD vs. THC
“Medical cannabis” typically refers to using the cannabis plant or its chemical components for health purposes. The plant contains dozens of cannabinoids, but the two primary ones are THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol). These interact with our body’s endocannabinoid system – a network of receptors in the brain and body involved in regulating mood, memory, pain, and more [1]. THC is psychoactive, responsible for the classic marijuana “high,” while CBD is non-intoxicating and may even counteract some of THC’s effects [2].
Autism Spectrum Disorder and Cannabis
Some studies and surveys suggest that CBD-rich cannabis extracts may help reduce anxiety, aggression, and sleep disturbances in individuals with autism [3]. In a 2019 Israeli study of 188 children with autism, 30.1% reported significant improvement in symptoms after six months of CBD-rich cannabis oil treatment [4]. However, responses vary, and side effects like agitation or fatigue can occur. Most experts advise caution, particularly for children, due to the lack of large-scale, long-term studies [5].
Epilepsy and Seizure Disorders
CBD’s strongest evidence exists in the treatment of rare forms of epilepsy. The FDA-approved medication Epidiolex, derived from purified CBD, significantly reduced seizures in patients with Dravet syndrome and Lennox-Gastaut syndrome [6]. In one clinical trial, seizure frequency dropped by 39% for those on CBD compared to 13% in the placebo group [7]. While side effects like drowsiness and gastrointestinal issues are possible, CBD has generally been well tolerated [8].
ADHD
Despite anecdotal reports, there is little clinical evidence supporting cannabis as a treatment for ADHD. A 2023 review concluded that cannabis is not an effective or recommended therapy for ADHD due to a lack of controlled studies and potential cognitive side effects, particularly with THC use [9]. CBD may offer some calming benefits, but this too remains largely untested in rigorous trials.
Anxiety and PTSD
CBD has shown potential in reducing anxiety in both animal studies and human trials. A 2023 University of Colorado study found that adults using CBD-dominant cannabis reported significantly lower anxiety levels compared to those using THC-dominant strains or no cannabis at all [10]. THC may reduce anxiety at low doses but worsen it at higher doses, especially in sensitive individuals [11].
Parkinson’s Disease
While cannabis has not been shown to reverse motor symptoms in Parkinson’s, some patients report improvements in sleep, pain, and quality of life. A 2020 review found limited but promising evidence supporting CBD and low-dose THC for managing non-motor symptoms in Parkinson’s patients [12]. However, THC can worsen confusion and balance issues, particularly in older adults [13].
Pediatric vs. Adult Use
Age is a critical factor in cannabis use. Children and adolescents are more vulnerable to THC’s psychoactive effects and potential impacts on brain development. For this reason, most pediatric cannabis treatments focus on CBD, especially for conditions like epilepsy or severe autism [14]. In adults, the risk profile is different, though caution is still warranted, especially for older adults prone to falls or cognitive impairment.
Pros and Cons Summary
Pros:
- Symptom relief for seizures, anxiety, pain, sleep disorders
- Quality of life improvements
- Alternative when conventional treatments fail
- CBD is generally well tolerated
- Multi-symptom management in one therapy
Cons:
- Side effects: fatigue, gastrointestinal issues, cognitive impairment (THC)
- Psychiatric and cognitive risks, especially in youth
- Lack of long-term data, especially in pediatrics
- Variable response and inconsistent product quality
- Risk of dependency (mainly THC)
- Legal and regulatory barriers
- Potential drug interactions
Legal and Ethical Considerations
Cannabis legality varies widely. As of 2024, 38 U.S. states allow medical cannabis, but it remains federally illegal [15]. Other countries like Canada, Israel, and Germany have legalized or decriminalized medical use. Pediatric access typically requires extensive medical documentation and often limits products to CBD-only formulations [16]. Ethically, the use of cannabis in children must be weighed against risks, especially when evidence is limited.
Conclusion
Cannabis shows promise for managing symptoms associated with autism and neurological disorders, particularly CBD for epilepsy, anxiety, and possibly autism. THC may be useful in select cases but comes with greater risk, especially for young or vulnerable individuals. As research expands, clearer guidelines and better products will help clinicians and patients make informed, safe decisions. Until then, cannabis should be considered a tool—one with potential, but not without risk.
Footnotes / Sources
- National Institutes of Health – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173675/
- Harvard Health Publishing – https://www.health.harvard.edu/blog/medical-marijuana-and-cbd-whats-the-difference-2020010618648
- Autism Speaks – https://www.autismspeaks.org/news/cannabis-and-autism-what-do-we-know
- Aran A. et al. (2019). “Cannabis in autism: A retrospective study.” Scientific Reports – https://www.nature.com/articles/s41598-019-48175-4
- Frontiers in Psychiatry – https://www.frontiersin.org/articles/10.3389/fpsyt.2021.707442/full
- U.S. FDA – https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-comprised-active-ingredient-derived-marijuana-treat-rare-severe-forms
- Devinsky O. et al. (2017). “Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome.” New England Journal of Medicine – https://www.nejm.org/doi/full/10.1056/nejmoa1611618
- Devinsky O. et al. (2018). “Long-term safety and treatment effects of cannabidiol in children and adults with treatment-resistant epilepsies.” Epilepsia – https://onlinelibrary.wiley.com/doi/full/10.1111/epi.14477
- American Journal of Psychiatry – https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2023.22101238
- University of Colorado Boulder – https://www.colorado.edu/today/2023/06/20/new-study-finds-how-cannabis-affects-anxiety
- Journal of Cannabis Research – https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-021-00060-1
- Kluger B. et al. (2020). “Cannabis and Parkinson’s Disease.” Journal of Parkinson’s Disease – https://content.iospress.com/articles/journal-of-parkinsons-disease/jpd191837
- Parkinson’s Foundation – https://www.parkinson.org/Understanding-Parkinsons/Treatment/Complementary-Therapies/Medical-Marijuana
- American Academy of Pediatrics – https://publications.aap.org/pediatrics/article/135/3/584/74350/The-Impact-of-Marijuana-Policies-on-Youth
- National Conference of State Legislatures – https://www.ncsl.org/health/state-medical-cannabis-laws
- American Medical Association – https://www.ama-assn.org/delivering-care/public-health/what-doctors-need-know-about-medical-marijuana
