CBD And Autism, What Does The Research Suggest?

Autism exists on a spectrum

Our understanding of autism has grown significantly in the last thirty years. It is no longer a single condition; instead, it is diagnosed on a spectrum. Despite a better grasp of ASD’s symptoms, we still do not know the exact triggers for its onset. The difficulty associated with tackling ASD also comes from its overlap with conditions like seizures and intellectual disabilities.

Symptoms of autism spectrum disorder are vast and varied. By broadening the signs accepted for a diagnosis, we can identify ASD at an earlier age. The condition is also being diagnosed retrospectively based on accounts of how an adult behaved during their childhood.

ASD is typically defined as persistent problems in social communication and interaction with repetitive arm or hand movements. No matter the situation, there is an apparent inability to communicate effectively, both verbally and non-verbally. The individual also needs to show signs of a restricted or repetitive pattern of behaviour. This can manifest in repeated greetings, rituals, or obsession over inanimate objects.

Diagnosis of ASD is vastly improving

It is thanks to the latest iteration of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published in 2013, that we have come to better understand and identify ASD. It is estimated that ASD affects 1% of people across the world (62.2 million globally as of 2015). The rise in ASD diagnosis may be alarming, but it is a positive step.

Conventional treatment mainly consists of behavioural exercises, but patients may be prescribed medication. However, the ineffectiveness of traditional medicines has led to a renewed focus on alternative treatment methods. The world’s greatest researchers are currently looking to the endocannabinoid system instead. The interaction between our endocannabinoid system (ECS) and cannabinoids may hold the key to treating ASD.

Pre-clinical research

Below is a sample of some of the groundbreaking research taking place. These studies represent some of the most prestigious medical institutes working alongside respected and revered researchers.

Zamberletti’s important review 2017 - endocannabinoid system (ECS); plays a role in autism

To begin with, we have a review that brings together three separate pre-clinical trials and their findings.

One potential trigger for ASD is Fragile X syndrome. It is considered the most common genetic cause of ASD. By replicating the gene in mice, researchers could monitor signalling of the endocannabinoid system. Their findings showed that by regulating enzymes that cause these signals to become disrupted, there was an improvement in autism behaviours.

In a similar scenario, substances were again administered to rats that inhibited the breakdown of the endocannabinoid anandamide (AEA). This was used to see if it would counteract the damaging side effects of an anti-epileptic drug called VPA. Some studies suggest VPA may contribute to the development of ASD when taken during pregnancy. Results showed a “decrease in the autism-model behaviours” in the rats with a greater presence of AEA.

Finally, bacterial and viral infections have also been linked to the development of ASD when either is experienced during pregnancy. By replicating the immune system's response to influenza in pregnant rodents, researchers noted “reduced CB1 (cannabinoid receptor) binding” in offspring. Their findings could suggest that an underactive endocannabinoid system is linked to ASD.

Dr. Adi Aran - world’s first pre-clinical research on humans

Pre-clinical trials are nearly always conducted on rat models. However, Dr. Adi Aran’s pioneering study marks the first pre-clinical trial to try and evaluate the use of cannabis for treating autism in children. Operating out of the Shaare Zedek Medical Centre in Jerusalem, 60 children were treated with an orally administered mixture containing both CBD and THC. The mix featured a 20:1 ratio in favour of CBD. 

All the children had been diagnosed with ASD and were aged between five and eighteen. Patients found “behavioural outbreaks were much improved or very much improved in 61% of patients”. In regards to difficulty communicating, 47% of patients reported improvement. Adverse side effects included sleep disturbances (14%), irritability (9%), and a loss of appetite (9%).

While there is still an incredible amount we need to learn about CBD’s feasibility as a treatment option, the findings support the need for a larger trial with double the amount of participants. Thankfully, the Israeli government agreed, and Dr. Adi Aran was able to progress from a pre-clinical trial to a larger clinical trial.

Clinical trials

Cannabinoids for Behavioral Problems in Children With ASD (CBA)

In moving to a clinical trial, Dr. Adi Aran was able to increase the scale of his study. The original pre-clinical trial featured 60 children; this time, 150 participants were enrolled. The research was based on a double-blind, randomised, placebo-controlled trial.

Still underway, the estimated completion date is July 2019. The study is using a similar cannabinoid formula (CBD:THC, 20:1) created using whole plant extraction. This means the key chemical components of cannabis will be retained, rather than isolated, before being mixed with olive oil.

Cannabidivarin (CBDV) vs. Placebo in Children With Autism Spectrum Disorder (ASD)

Carried out over 12 weeks, 100 child participants are currently being reviewed to see how CBDV impacts their symptoms of ASD. Similar to CBD, CBDV is being matched with a placebo to ensure the integrity of results. The study, conducted by Eric Hollander at Montefiore Medical Center is in collaboration with the United States Department of Defence. It will, however, be some time before we see the outcome. The clinical trial is due to be completed in September 2021.

Shifting Brain Excitation-Inhibition Balance in Autism Spectrum Disorder

In the UK, King’s College London is also exploring the possibility of cannabinoids in the effective treatment of ASD. Thirty-eight adult men, some with ASD and some without, will be given acute doses of CBD and CBDV alongside a placebo. Special imaging equipment will then be used to map their brain biochemistry during the trial. Planned completion is April 2019. Dr. Grainne McAlonan who is leading the study comes highly regarded for her work in the field of neuroscience.