cbd oil low thc for autism

Cbd oil low thc for autism

Objectives To assess whether autistic and non-autistic adults differ in their cannabis and cannabidiol (CBD) use, their perceptions of cannabinoid products and their cannabinoid-related support-seeking behaviours.

Design Cross-sectional survey.

Participants Respondents to an online survey, who self-reported an autism-spectrum disorder diagnosis (autistic participants) or no issues relating to autism (controls). Exclusion criteria were: related/subclinical issues relating to autism, non-UK residence, under 16 years old. Propensity score matching was used to match autistic participants and controls on age, gender and ethnicity. The full-sample analysis included 269 participants and the propensity-matched sample analysis included 166 participants. Propensity-matched analysis was used for primary analysis and was considered robust if supported by triangulation with full-sample analysis.

Results Autistic participants were more likely to have used CBD in the past 12 months compared with controls (OR=3.52, 95% CI 1.57 to 7.87, p=0.002). They used CBD on more days in the past 12 months (M=34, SD=93) compared with controls (M=17, SD=69, p=0.002). Autistic participants reported trusting the news and doctors less as sources of cannabinoid-related information than controls (p=0.024 and p=0.003, respectively). Autistic participants endorsed the following barriers to cannabinoid-related support seeking more than controls: ‘worrying they won’t understand me’ (OR=3.25, 95% CI 1.67 to 6.33, p<0.001), ‘going somewhere unfamiliar’ (OR=5.29, 95% CI 2.62 to 10.67, p<0.001) and ‘being in a crowded or chaotic place’ (OR=9.79, 95% CI 4.18 to 22.89, p<0.001).

Conclusion Results indicate a higher prevalence and frequency of CBD use, but not cannabis use, among autistic individuals compared with controls. Findings also suggest appropriate methods to disseminate cannabinoid-related support to autistic individuals, and indicate differences in the potential barriers autistic and non-autistic individuals may face when seeking cannabinoid-related support.

  • public health
  • epidemiology
  • substance misuse

Data availability statement

No data are available. Data from this study is unable to be shared as participants did not consent to data sharing.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

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Strengths and limitations of this study

Propensity score matching allows differences between autistic and non-autistic participants to be likelier attributable to autism-spectrum disorder.

Triangulation of the matched sample analysis to a full-sample analysis increases the robustness of findings when considering exclusion bias introduced through matching.

Autistic and non-autistic participants were matched on age, gender and ethnicity. It is possible that non-included or unmeasured variables still represent confounding factors.

Given the exploratory nature of this research, correction for multiple testing was not applied for the majority of analysis. Results should, therefore, be interpreted cautiously.

Autistic participants were predominantly White, university-educated, and their self-reported diagnoses were not verified by a clinician. Results may not generalise across ethnicities or to individuals who are unable to access online research studies.


Autism-spectrum disorder (ASD) is a neurodevelopmental condition defined by social communication difficulties and restricted, repetitive behaviours.1 ASD may be additionally associated with anxiety and low mood among other challenges.2 3

To manage these challenges, autistic individuals may self-medicate using substances.4 Studies have shown autistic individuals to be two to four times more likely to endorse tobacco, alcohol or other drug-related problems compared with their non-autistic relatives.5 Even in those without an ASD diagnosis, autism-related difficulties including social communication difficulties and repetitive behaviours may be associated with greater tobacco, alcohol and cannabis use, as evidenced by a large survey of the general adult population.6 These findings may indicate that substances are used to alleviate difficulties associated with ASD, which is noted in qualitative interviews with substance-using autistic individuals.7 In line with this notion of self-medication, expectancy theory proposes that substance use is motivated by expectancies that this behaviour will produce a positive effect.8 A previous study found that the expectancy that alcohol would benefit autism-related difficulties was associated with higher frequency of alcohol use in autistic individuals.9 However, expectancies among autistic individuals for other substances have been understudied. One such group of substances is compounds derived from the cannabis plant, called cannabinoids. The two most abundant of these are cannabidiol (CBD), a non-intoxicating cannabinoid, and delta-9-tetrahydrocannabinol (THC), which is intoxicating.

Cannabinoids may help mitigate several difficulties that can be associated with ASD. Epilepsy has been regarded as a frequent comorbidity and exacerbator of behavioural difficulties in autistic individuals.10 Recently, CBD was approved as an effective treatment for certain forms of epilepsy. Additionally, some evidence suggests that there may be a more substantial effect when CBD is combined with THC.11 Autistic individuals may also face difficulties with recognising emotions.12 A randomised placebo-controlled trial found that a single dose of CBD improved emotional face recognition, whereas THC impaired performance on the same task.13 Animal studies have further shown CBD to exert agonist effects on 5-HT1a serotonin receptors similarly to antidepressants, and so CBD may produce benefits to mood and anxiety.14 THC may also have benefits for autistic individuals by reducing locomotor activity15 and in tandem with CBD, improve on hyperactivity and impulsivity.16 Most recently, a double-blinded randomised controlled trial of CBD and THC in a 20:1 ratio found significant improvements to social responsiveness and disruptive behaviours compared with placebo, among 150 autistic children and adolescents.17

While some research indicates potential medicinal uses of cannabinoids for autistic individuals, current research on efficacy and safety is limited18. Therefore, cannabinoids are currently not approved as pharmacological interventions for ASD. In the absence of prescribed cannabinoids, or any pharmacological intervention for autistic individuals,19 some may turn to non-prescribed cannabinoid use. A growing public interest in the use of cannabinoids for medicinal or wellness purposes may facilitate such behaviours.20 Within the UK, non-prescribed use of cannabinoids largely takes the form of CBD products, which are legally available in health food shops and online, and of non-prescribed cannabis, which is currently illegal.21

Overall, CBD has been regarded as a well-tolerated drug with few side effects.22 23 However, levels of CBD in available CBD products are typically far lower than those administered in clinical trials;24 hence, the effectiveness of these products remains unknown. Moreover, THC levels in these products are often variable and have been found at times to exceed legal limits in some jurisdictions.25 Thus, CBD products may currently lack quality assurance and data on their safety or efficacy. It is notable that the recent classification of CBD as a novel food by the European Food Standards Agency has facilitated tightened safety regulations within the UK since March 2021, which may influence these issues with CBD products in the future.26 Conversely, cannabis use has been associated with increased risk of developing cannabis use disorder and psychosis.27 28 These effects are attributable to THC, which has been shown during acute administration to produce transient psychotic symptoms and impaired memory in a dose-dependent manner.29

Despite the potential risks of cannabis and the lack of quality assurance for CBD products as well as the potential benefits of cannabinoids for ASD, there is a current lack of data on the prevalence and characteristics of their use, across autistic and non-autistic individuals. Current data are limited to diagnosis rates of substance use disorders among autistic adults,30 31 which fails to capture subclinical cannabinoid use, and how and why autistic individuals use these products. Without this information, the extent of potential benefits or harms caused by unregulated cannabis use among autistic people remains unknown. Moreover, this precludes understanding the aetiological factors of cannabinoid use for autistic individuals, which impedes the development of evidence-based support programmes.32 To address this gap in the literature, we sought to provide a comprehensive survey of cannabinoid-related behaviours in autistic versus non-autistic individuals, including prevalence and frequency of use, expectancies regarding cannabis and CBD, cannabinoid-use support-seeking behaviours and whether cannabis/CBD use is associated with use of other drugs.


Participants and design

A cross-sectional, observational online survey design was used. The survey was open from 4 February to 7 April 2020. Participants were contacted to participate from the Centre for Applied Autism Research, the University of Bath Research Participation Scheme, the Cambridge Autism Research Database and via direct recruitment of friends and family by university students. Participants recruited via the Research Participation Scheme were given course-relevant credits and no other reimbursements were given. Inclusion criteria were as follows: fluency in written English and residing within the UK. Exclusion criteria were as follows: non-UK residence, not providing consent to analyse data, related/subclinical issues relating to ASD and under 16 years old.

Procedure and measures

Respondents accessed the online survey on their personal devices. Respondents were asked for demographic and clinical information. Two questions were then asked regarding autism-related difficulties: ‘How often do you have difficulties with social communication and social interaction with other people? (eg, difficulties with normal back-and-forth social conversation or making normal eye contact or making friends)’ and ‘How often do you have difficulties with restricted and repetitive patterns of behaviours, activities or interests? (eg, difficulties with repetitive movements, or insisting on sameness (or routines), or fixated and intense interests, or very high (or very low) sensitivity to the environment, such as light, sound or texture’. Both questions used a 5-point rating scale: 0 (almost never/in almost no situations), 1 (rare/in rare situations), 2 (sometimes/in some situations), 3 (mostly/in most situations) and 4 (almost always/in almost all situations). These questions have been demonstrated to distinguish autistic and non-autistic individuals and correlate with established measures of autistic-like traits.33 These questions functioned to confirm that individuals who self-reported an ASD diagnosis did endorse autism-related difficulties to levels seen in previous published samples of autistic individuals.9 33

Respondents were then asked whether they had used alcohol, tobacco, cannabis or CBD products within the past 12 months. Subsequently, respondents were asked to rate how frequently they used cannabis and/or CBD products in the past 12 months, using the following scale: (1) not in the last year, (2) once or two times a year, (3) once every couple of months, (4) once or two times a month, (5) once or two times a week, (6) 3 or 4 days a week, (7) 5 or 6 days a week and (8) almost every day.

Alongside this, respondents completed the Severity of Dependence scale (SDS)34 for cannabis and then CBD. Five items are scored on a 4-point scale with higher scores indicating greater dependence. A diagnostic cut-off for cannabis dependence has been suggested at a total score of at least 3.35 The SDS has demonstrated strong internal and test–retest reliabilities, and good discriminant and construct validities in assessing dependence among several substances, including cannabis.36 Within this study, internal reliability was good for cannabis (α=0.838) and CBD (α=0.845).

Respondents were then given a 15-item questionnaire adapted from a previous study on alcohol9 to assess cannabis and CBD expectancies. The first six items relate to commonly endorsed expectancies for substance use identified in the general population37 (1) global positive changes, (2) changes in social behaviour, (3) improved cognitive and motor abilities, (4) sexual enhancement, (5) cognitive and motor impairment and (6) relaxation and tension reduction. The next seven items are autism-specific expectancies related to diagnostic criteria for autism-spectrum disorder1 (1) verbal communication; (2) non-verbal communication; (3) developing, maintaining and understanding relationships; (4) stereotyped or repetitive motor movements; (5) insistence on sameness; (6) highly restricted, fixated interests and (7) hyper-reactivity or hyporeactivity to sensory stimuli. Finally, two medical expectancies were included: (1) medicinal properties and (2) safety. A 5-point scale was used for this questionnaire, from (1) almost never/never to (5) almost always/always.

Following this, respondents were asked to rate the extent they agreed that accurate information and labelling of cannabis and CBD products were available to them on visual analogue scales from 0 (least agree) to 100 (most agree). Respondents were then asked to rate how much they trusted certain sources when finding out information about cannabis and/or CBD products from 0 (least trust) to 100 (most trust).

Finally, respondents were asked if they were to experience excessive cannabis/CBD use, where they would go for help, and what they would perceive as barriers to support-seeking. A full view of the survey, including all measures, may be seen in online supplemental materials.

Supplemental material

Public involvement statement

No members of the public were involved in the design or analysis of this study. A draft of the manuscript was reviewed by an autistic individual, to ensure that the commentary of the study was appropriate and not out of line with the lived experiences of an autistic person. Specifically, they commented that the available support after their autism diagnosis was very limited, and this study’s findings were concordant with their own use of CBD oil as a form of self-medication. Additionally, they reported that the identity-first language used in this paper (ie, ‘autistic person’ rather than ‘person with autism’) was preferred, as was the focus on the perspective of autistic individuals rather than the perspective of carers.


The focus of our analysis was to compare autistic and non-autistic individuals on cannabinoid use behaviours and related factors. In order to account for the likelihood that autistic participants differed on key demographic variables to control participants, propensity score matching on age, gender and ethnicity was conducted to obtain groups with similar demographics. This allows differences between groups to be likelier attributable to ASD. Following recommendations, 1:1 nearest neighbour logistic regression matching with replacement, with a tolerance level of 0.03, was chosen.38 39 Several authors have noted matching with or without replacement is generally comparable, and, indeed, this produced the same sample size in the current study.40 41 Given the reduction in confounding by demographic factors in the matched sample, this method is more conservative than the full-sample analysis and was chosen as the primary method for analysis. Elimination of data to obtain matched samples may, however, introduce exclusion bias. Therefore, to ensure that any case–control differences were robust to different analytical methods, propensity score matching results were triangulated with full-sample analysis results. Group differences were only considered robust if supported by triangulation between propensity score matching and full sample analysis results.42

Differences between autistic and control groups were assessed using χ 2 independence tests, Fisher’s exact tests, independent-sample t tests, and Mann-Whitney U tests as appropriate with an alpha level of 0.05. Effect sizes were computed as ORs or r (Z/(√N) for χ 2 independence tests and Mann-Whitney U tests, respectively. Post-hoc Spearman’s Rho correlations were used to assess within-group associations between autism-related difficulties (social communication difficulties and restricted, repetitive behaviours) and frequency of cannabis/CBD use, using Bonferroni-adjusted alpha levels of 0.025 (0.05/2). Post-hoc Spearman’s Rho correlations were also used to assess within-group associations between expectancies of cannabis/CBD use and frequency of cannabis/CBD use, using Bonferroni-adjusted alpha levels of 0.0125 (0.05/4). No adjustment was made for other analyses. Missing data were handled through pairwise deletion.


A total of 378 respondents accessed the survey. Thirty-two respondents were excluded due to non-UK residence, and 62 respondents did not provide consent to take part. Fifteen respondents indicated they did not have a formal ASD diagnosis but had related, subclinical issues. To ensure the group of autistic individuals was consistent, and to obtain a comparison between ASD diagnosed and non-ASD diagnosed groups, we excluded these respondents from analysis. Finally, propensity score matching to obtain a matched sample resulted in the exclusion of 103 participants. The final sample size was 166. Matched sample characteristics are seen in table 1, while full sample characteristics can be viewed in online supplemental table S1.

Demographic and clinical information for propensity score matched autistic and control participants

As shown in table 2, autistic participants were significantly less likely to have drank alcohol in the past 12 months compared with control participants, and this finding was supported by the full-sample analysis (online supplemental table S2). Groups were comparable in their use of tobacco in the past 12 months.

Prevalence and frequency of substance use and severity of dependence, among autistic and control participants

Autistic participants were significantly more likely to have used CBD in the past 12 months compared with control participants, and this finding was supported by the full-sample analysis (online supplemental table S2). Groups were similar in their use of cannabis in the past 12 months.

Autistic participants used CBD significantly more frequently compared with control participants, with a small-to-medium effect. This was supported by the full-sample analysis (online supplemental table S2). No differences in frequency of cannabis use between groups were found. Autism-related difficulties (social communication difficulties and restricted, repetitive behaviours) were not significantly correlated with frequency of cannabis or CBD use in the past 12 months, within either the autistic or control groups (all p values >0.05).

Both groups had comparable severity of dependence scores, for cannabis and for CBD.

In autistic participants, alcohol use was significantly associated with CBD use, while tobacco use was significantly associated with cannabis use in both autistic and control participants (online supplemental materials).

Table 3 shows between-group differences in cannabis use and CBD use expectancies. Groups were comparable on recreational drug use and autism-specific expectancies for cannabis use and whether they thought cannabis was safe and had medicinal properties. In the control group, frequency of cannabis use in the past 12 months was significantly positively correlated with recreational drug use expectancies, rs=0.356, p=0.001, N=80, the expectancy that cannabis is safe, rs=0.563, p<0.001, N=81 and the expectancy that cannabis has medicinal properties, rs=0.284, p=0.010, N=81. In the autistic group, frequency of cannabis use in the past 12 months was significantly positively correlated with recreational drug use expectancies, rs=0.348, p=0.001, N=82, and the expectancy that cannabis is safe, rs=0.424, p<0.001, N=83. All other correlations were non-significant. Differences in non-grouped cannabis expectancies between autistic and non-autistic individuals are shown in online supplemental table S3.

Expectancies of cannabis and CBD use among autistic and control participants

Control participants endorsed recreational drug use expectancies of CBD use to a significantly greater extent compared with autistic participants, with a small-to-medium effect that was also supported by the full-sample analysis (online supplemental table S4). Groups were comparable on the extent they endorsed autism-specific expectancies of CBD use, whether CBD was safe and whether it had medicinal properties. In the control group, frequency of CBD use in the past 12 months was significantly positively correlated with the expectancy that CBD has medicinal properties, rs=0.345, p=0.002, N=77, and the expectancy that CBD is safe, rs=0.343, p=0.002, N=77. In the autistic group, frequency of CBD use in the past 12 months was significantly positively correlated with the expectancy that CBD is safe, rs=0.321, p=0.003, N=82. Differences in non-grouped CBD expectancies between groups are shown in online supplemental table S5.

Autistic and non-autistic participants were comparable in how they perceived the accuracy of information conveyed to them about cannabis and CBD (online supplemental table S6).

Table 4 displays autistic and non-autistic participants’ ratings of trust for various sources of information regarding cannabinoids. Autistic participants trusted ‘News’ less than controls, with a small-to-medium effect size. Similarly, the autistic group reported less trust for doctors compared with controls, with a small-to-medium effect. Both of these group differences were replicated within the full-sample analysis (online supplemental table S7). All other sources of information were perceived to be equally trustworthy by autistic and non-autistic participants.

Perceived trustworthiness of sources for cannabis/CBD information, among autistic and control participants

No significant differences were found between autistic and non-autistic participants for who they stated they would seek support for reducing cannabis/CBD use from. Searching online for information and going to the doctor/GP were the two most popular sources of support for autistic participants, both endorsed by 56.6% of autistic participants. See online supplemental table S8 for full details.

Barriers to seeking support for cannabis/CBD use are shown in table 5. Autistic participants, compared with control participants, were significantly more likely to endorse the following as barriers: worrying they would not be understood, going somewhere unfamiliar and being in a crowded or chaotic place. All of these group differences were supported by the full-sample analysis (online supplemental table S9).

Barriers to seeking support for cannabis/CBD use among autistic and control participants


Principal findings

To our knowledge, this is the first study to compare autistic and non-autistic individuals on their use of cannabis and CBD. Autistic participants were found to use CBD more and cannabis to a similar extent compared with non-autistic participants. However, autism-related difficulties (social communication difficulties and restricted, repetitive behaviours) were not correlated with frequency of cannabis or CBD use in the past 12 months, for both autistic and non-autistic participants. Cannabis and CBD use expectancies were similar between autistic and non-autistic participants, except recreational drug use expectancies for CBD which were lower for autistic participants. Recreational drug use expectancies for cannabis were positively correlated with frequency of cannabis use in the past 12 months, for both autistic and non-autistic groups. Medical expectancies regarding safety and medicinal properties were also positively correlated with frequency of cannabis and CBD use in both groups. Perceptions of accuracy for cannabinoid-related information were similar for autistic and non-autistic participants, though autistic participants were found to trust the news and doctors less as sources of information regarding cannabinoids. Potential barriers to cannabinoid-related support seeking that autistic participants endorsed more than non-autistic participants included not being understood, and going somewhere unfamiliar, crowded and chaotic.

Strengths and limitations

Strengths of this study include the use of propensity score matching and triangulation with full-sample analysis, to ensure that findings were robust to different analytical approaches. Thus, by limiting our interpretation of group differences to those where both matched and full samples produced corroborating results, our findings can be considered more robust.42 Limitations of this study include a lack of correction for multiple comparisons in the majority of analysis. This was chosen given the novel and exploratory nature of this research, though findings should, therefore, be interpreted cautiously and require further replication. Additionally, this study was restricted to UK residents and failed to capture cross-national differences in cannabinoid usage rates as well as cultural and policy views regarding cannabinoids.43 This study’s sampling methods may also limit the generalisability of findings. Given the technological abilities required to access the online survey and the high proportion of university-educated participants, findings may not be representative of autistic individuals with co-occurring learning disability. Generalisation across ethnicities may also be limited given the high proportion of the sample that were White. Sampling limitations, such as these have been previously discussed within cannabis and autism-related research,44 45 and future studies may wish to consider targeted recruitment towards hard-to-reach autistic populations. It is also important to note that a proportion of autistic and non-autistic participants had psychiatric comorbidities, which have been demonstrated to affect substance use and self-medication attitudes.46–48 Finally, ASD diagnoses were self-reported and not verified by a trained clinician.

Relationship to previous literature

In this study, autistic participants were more likely to have tried CBD in the past 12 months and used it more frequently, compared with non-autistic participants. However, frequency of CBD use in the past 12 months was not correlated with autism-related difficulties, which does not support the notion that autistic individuals self-medicate using CBD in response to particular aspects of ASD. In understanding the reasons why autistic individuals may use CBD, it is notable that diagnosis rates for anxiety and depression were higher in the autistic versus control group, which is in line with previous findings.49 Anxiety and depression have been previously found to be common reasons for CBD use,50 and it may be that autistic individuals are choosing to use CBD to self-medicate anxiety or depression rather than autism per se. However, current findings are unable to confirm the reasons autistic participants used CBD, and this may represent an area for further inquiry.

Previous studies have found ASD diagnoses and autistic traits to be associated with cannabis use and increased risk of drug use disorder, supporting the notion of self-medication.5 6 In contrast, this study did not find cannabis use nor severity of cannabis dependence to be elevated in autistic participants. Given contradictory findings, further research may be warranted.

Expectancy theory proposes that expectancies motivate substance-using behaviours,8 and our results provide partial support for this proposition. Recreational drug use expectancies were associated with frequency of cannabis use for both autistic and non-autistic participants. Medical expectancies were also associated with frequency of cannabis and CBD use in both groups. However, autism-specific expectancies were not associated with frequency of cannabis or CBD use, and recreational drug use expectancies were not associated with frequency of CBD use. This contrasts a previous study, which found autism-specific expectancies to be associated with more frequent alcohol use among autistic individuals.9 Since alcohol is readily available for purchase by adults, expectancies may be the dominant factor determining alcohol use, while cannabis and CBD use may be determined by additional factors such as illegality and high prices.21 51


These findings indicate appropriate avenues to disseminate cannabinoid-related information and support to autistic individuals. Compared with non-autistic participants, autistic participants trusted the news and doctors less as sources of information regarding cannabinoids. Scientific journals and National Institute of Health and Care Excellence (NICE) were rated as the most trusted sources by autistic individuals. Current NICE guidelines on medicinal cannabinoids do not mention its relevance to ASD,52 although these findings indicate this information could positively inform cannabinoid use for autistic individuals. Additionally, our findings corroborate previous work9 that the internet is among the most popular sources for substance-related support, reiterating the importance of high-quality, accessible guidance online.

Finally, this study highlights the benefits of autism-relevant adjustments within substance use services. Autistic participants endorsed that not being understood, being somewhere unfamiliar and going to a crowded, chaotic place were potential barriers to cannabinoid-related support seeking, more so than non-autistic participants. These potential barriers were also identified by previous work9 as highly prevalent for autistic individuals in relation to alcohol-related support seeking and together suggests targets to improve accessibility of care. Notably, a transition to remote services due to the SARS-CoV-19 pandemic may lessen these barriers, and it will be pertinent to investigate how these changing services are experienced by autistic individuals.53 Furthermore, future research may wish to assess how autistic individuals access cannabis, as these barriers may potentially suggest a preference away from approaching cannabis dealers in-person if this involves unfamiliar or chaotic environments.


This study used propensity score matching and triangulation to examine differences between autistic and non-autistic participants in their cannabinoid use and related beliefs. Our findings indicate a higher prevalence and frequency of CBD use, but not cannabis use, among autistic individuals compared with non-autistic individuals. Findings also suggest appropriate methods to disseminate cannabinoid-related support and guidance to autistic people and highlight potential barriers to target in improving access to cannabinoid-related support.

Data availability statement

No data are available. Data from this study is unable to be shared as participants did not consent to data sharing.

Ethics statements

Patient consent for publication

Ethics approval

This study involves human participants and was approved by the University of Bath Psychology Research Ethics Committee (Code: 19-317). Participants gave informed consent to participate in the study before taking part.


We would like to thank Will Reid, Kristi Mandova, Prarthana Sabharwal, Scarlet Jenne, Noor-Alhuda El-Amin and Wenjing Yu who assisted with data collection, and the autistic individual who kindly reviewed our manuscript. We are grateful to the Autism Research Centre at the University of Cambridge for access to the Cambridge Autism Research Database as a source of recruitment.

Autism and Cannabis: Here’s What the Science Says

Many parents have seen firsthand the calming, clarifying effect that cannabidiol (CBD) has on their autistic children. Yet most mainstream medical professionals remain skeptical about the effectiveness and safety of using medical cannabis to treat autism. Even politicians are divided: Earlier this month Colorado Gov. John Hickenlooper vetoed a bill passed by the state legislature that would have added autism as a condition that qualifies for medical cannabis.

What does the science say? Like many conditions treated with medical marijuana, the personal experience and anecdotal evidence currently runs far ahead of the peer-reviewed scientific research.

Autism is often accompanied by epilepsy, leading some to suspect that CBD could allay both conditions.

Autism Spectrum Disorders (ASDs) are lifelong neurodevelopmental conditions that involve differences in language, behavior, and social interaction. It’s worth acknowledging that autism can be a highly contentious issue. The very definition of ASD/autism can spark debate among parents and experts. An emerging neurodiversity movement, for instance, has coalesced around the idea that conditions such as autism, ASD, and ADHD aren’t pathologies to be treated but differences to be respected. Autism has long been defined as a cognitive deficit. For those in the neurodiversity movement, it’s a cognitive difference.

Parents Searching for Relief

Brandy Williams’ experience is typical of the parents who use medical cannabis as part of their child’s treatment. Williams is the parent of an 8-year-old son, Logan, who was diagnosed with ASD a few years ago. By the age of five, Logan had exhibited countless examples of aggressive behavior: biting her, banging his head more than 150 times a day, and worse. Logan had even knocked out his own teeth—twice. Williams tried nearly 50 hours of therapy, but it didn’t seem to help.

In addition to ASD, Logan also suffered from epileptic seizures. That’s not unusual among people living with autism. Researchers have noted that ASD is often accompanied by other neurological disorders, which could arise from an underlying central nervous system condition.

Epilepsy is commonly reported to occur in about one-third of people with ASD, but scientific studies have turned up a wide spectrum of co-morbidity ranging from 5% to 46%.

In Logan’s case, his epilepsy diagnosis actually helped his overall situation with regard to medical marijuana.

Autism as a Qualifying Condition

Autism is a qualifying condition in these states: Cannabis may be recommended by doctors for many conditions, including autism, in these states:
Delaware California
Pennsylvania Michigan
Minnesota Massachusetts
Georgia District of Columbia
South Carolina

In Arizona, Epilepsy Qualifies

Williams and her son live in Arizona, one of the many medical marijuana states that do not include autism as a condition that qualifies for medical cannabis. Arizona does include epilepsy on the list, however. (Leafly has a full list of Arizona’s qualifying conditions here.)

Years ago Logan’s mother tried to calm his symptoms by giving him hemp-derived CBD. That proved ineffective. But in June 2014, Arizona legalized the use of medical-grade cannabis for pediatric epilepsy patients. So Williams obtained a medical marijuana card for her son.

After a single dose of oil containing terpenes, CBD, and other cannabinoids (including a tiny amount of THC), Williams noticed a tremendous difference. Logan stopped rocking back and forth. His flapping hands calmed. After being completely nonverbal, Williams recalled, “Logan said 180 words in the first two months” of medical cannabis therapy.

Brandy Williams is one of many parents who have found medical cannabis to be effective in treating their child’s condition. Yet autism has yet to be accepted as one of the foundational conditions that qualify for medical marijuana in the 30 states that legally allow healthcare professionals to recommend it.

Only five states—Delaware, Pennsylvania, Minnesota, Georgia, and South Carolina—specifically include autism as a qualifying condition. A few others, including Michigan, California, Massachusetts, and the District of Columbia, don’t specifically include autism but allow doctors to recommend medical cannabis at their discretion as they see fit. Some parents of autistic children have accessed medical cannabis for their child to treat a qualifying co-morbid condition (such as muscle spasms or pain) and found that the cannabis allays some of the negative symptoms of autism as a side benefit.

Williams and her local chapter of MAMMA (Mothers Advocating Medical Marijuana for Autism, a group with active chapters in six states) have pushed Arizona regulators to add autism to the state’s MMJ list, but they’ve met with resistance from state officials.

@SonnyBorrelli & #MAMMAS‘ (Mothers Advocating for Medical Marijuana for Autism) Brandy Williams, prepare for a hearing on adding #Autism as a qualifying condition for AZ’S MMJ program. The world is turning … pic.twitter.com/TUwx5eTCQg

— mikel weisser (@mikelweisser) April 11, 2018

Most states don’t allow it, and yet some parents are adamant in their belief that it works. Why the disparity? Because the published research on cannabis and autism isn’t thin, vague, or contradictory. It’s practically nonexistent.

A 2015 Baseline Study

Three years ago, three scientists associated with Boston Children’s Hospital and Harvard University published what has become the baseline review of studies on cannabis and autism. They found research that showed slight promise, but nothing that definitively connected cannabis to an improvement in pediatric patients.

“At this time, good evidence is almost entirely lacking for its application in pediatric developmental and behavioral conditions,” wrote Scott Hadland, John Knight, and Sion Harris in the Journal of Developmental and Behavioral Pediatrics.

“Many advocates cite scientific literature regarding benefits of cannabis for the treatment of pediatric behavioral conditions,” they added, “but often, data cited are from animal model-based research that does not yet have translation to human subjects.”

They mentioned that:

  • A 2013 study from Stanford University showed that mice with a specific and rare gene mutation linked to autism showed altered endocannabinoid signaling in the central nervous system. These data were then cited by online and print media supporters of medical marijuana (for example, in the High Times) as evidence that cannabis could be used as a treatment for autism.
  • Another recent study based on a mouse model…showed alterations in endocannabinoid signaling pathways. These data were referenced (in this case, by more mainstream media outlets, such as the Huffington Post and Fox News) as evidence for a promising role for cannabis as treatment.

“Although these and other high-impact studies share important insights into the pathogenesis of ASD and fragile X syndrome, based on their results alone, it is erroneous and potentially harmful to conclude that cannabis should be used as treatment for either of these disorders at this time.”

“Given the current scarcity of data,” the authors conclude, “cannabis cannot be safely recommended for the treatment of developmental or behavioral disorders at this time. At best, some might consider its use as a last-line therapy when all other conventional therapies have failed.”

Cautious Authors

That’s a pretty strong cautionary statement. At the same time, it’s worth noting that Scott Hadland, the study’s lead author, has written many previous studies that view cannabis solely through the lens of addiction and youth substance abuse. He’s not done any firsthand research into the medical use of cannabis on autism or any other condition.

The conclusions of Hadland and his colleagues may ultimately prove to be overly cautious—or they may be wise words of advice. At the very least, if you’re a parent or patient talking with a physician about cannabis and autism, you should be aware that the Hadland overview is one of the main documents that mainstream doctors will be consulting.

Aside from anecdotal reports like those from Brandy Williams, what makes some in the autism community hopeful about the possibilities of cannabis as a healing agent?

Mostly it boils down to the potential links between epilepsy and autism. And when it comes to epilepsy and cannabis, there actually have been a number of peer-reviewed studies.

While only 2% of the general population suffers from epilepsy, one-third to one-fifth of people with autism suffer from epileptic seizures, according to a 2009 study by researchers at the National Institute of Mental Health.

“There’s definitely an association,” between autism and epilepsy, says Dr. Thomas Deuel, a neuroscientist who is an epilepsy specialist at Swedish Hospital in Seattle. “It’s not known why. The different brain development that occurs in autism is epileptogenic, meaning it’s more likely to create circuits that can cause seizures. Autistic brains develop differently.”

The link between epilepsy and autism led many parents like Brandy Williams to look into how medical cannabis might affect their child’s condition.

Cannabis Can Calm Seizures

Many—but not all—who have administered cannabis to epileptic children have seen promising results.

One of the earliest reports about the effects of cannabis on epilepsy involved Charlotte Figi, a young Colorado girl whose case later became world-famous.

Years ago, Figi suffered from a drug-resistant form of epilepsy called Dravet’s syndrome. Her seizures, which began when she was an infant, would sometimes last hours, and caused repeated heart failures. Sometimes she had hundreds of them in a week.

Her parents, after hearing of another boy helped by cannabis, gave her oil derived from a low-THC, high-CBD cannabis strain developed by the Stanley brothers, seven Colorado brothers who would go on to found the company Charlotte’s Web.

After ingesting the oil, Figi’s seizures slowed to a crawl. Her success led others to take a closer look at cannabis oil, and specifically at low-THC, high-CBD varieties of the plant.

Epilepsy Research Evolves

Orrin Devinsky, MD, a neurologist at the New York University Langone Medical Center, has been studying the effects of CBD on epilepsy. His recent study of Epidiolex, a drug under development by GW Pharmaceuticals, found that the medication reduced the frequency of seizures in epilepsy patients by as much as 42%.

In that study, published in May 2018 by the New England Journal of Medicine, one hundred and sixty two people were treated with 99 percent CBD—in addition to their already existing medications. While two percent became seizure free and 36.5 percent had reduction in seizures (similar to the rate of other drugs), many (79 percent) reported side effects like diarrhea, sleepiness, and fatigue. As Scientific American writes, “CBD is a potent liver enzyme inhibitor it can increase the concentration of other drugs in the body,” but because the study didn’t have a control group and it allowed for the patients to continue on their already prescribed drugs.

Devinsky told Scientific American: “I think, based on the evidence that we have, if a child has tried multiple standard drugs and the epilepsy is still severe and impairing quality of life, then the risks of trying CBD are low to modest at best,” Devinsky says. “[But] I do feel it is critical for us as a scientific community to get [more] data.”

CBD is the main active ingredient in Epidiolex, which is expected to receive final approval from the US Food and Drug Administration later this year.

The First Autism Studies

Researchers are only just now digging in to find out how cannabis can help those with autism.

In fact, two of the first such studies are being conducted by Orrin Devinsky, the same NYU neurologist who carried out the recent work on CBD (as Epidiolex) and epilepsy.

The double-blind study of 100 patients will include subjects between five and 18 years old with moderate to severe (4 or higher) autism. The study, done at the Montefiore Medical Center with Dr. Eric Hollander, will be examining the effects of CBDV, or cannabidivarin, which is similar to CBD, on the autistic patients. After the study is finished, the two doctors will conduct another trial involving CBD at New York University, Devinsky told Live Science.

Devinsky’s study is one of only two autism-and-cannabis projects listed on Clinicaltrials.gov, a database maintained by the National Institutes of Health. There are hundreds of studies worldwide exploring cannabis and various health effects, but only Devinsky’s and one other (run by Shaare Zedek Medical Center in Israel) specifically target autism and cannabis—and according to clinicaltrials.gov, they have yet to begin.

That may soon change. At the recent AutismOne national conference, Ronald Aung-Din, M.D gave a presentation, “The Neuromodulation: Treating Autism w Non-Systemic Direct Effects™ Cannabidiol” espousing the benefits of CBD on autistic patients, using “Direct Effects,” a trademarked topical CBD therapy.

Other research is being jump-started with significant funding. The University of California at San Diego, which has done a number of medical marijuana studies over the past two decades, recently received a $4.7 million gift for medical cannabis research specifically targeting how autism may be affected by cannabinoids.

The gift, from the Ray and Tye Noorda Foundation, is the largest private gift for cannabis research in the country.

“The more severe manifestations of autism are difficult to treat, causing parents to look for non-traditional remedies,” said Igor Grant, MD, professor of psychiatry and CMCR director in a press release. “There are unconfirmed reports that cannabidiol could be helpful, but there are no careful studies to document either its benefits or its safety.”

The 2017 Chilean Study

One report that sits somewhere between anecdotal report and careful study came out in Sept. 2017, at the World Congress of Neurology in Kyoto, Japan. Gisela Kuester, a neurologist specializing in the diagnosis and treatment of autism, presented a paper poster that reported positive results from a very small retrospective look at patients with ASD who were treated with cannabis extracts.

In a very small observational study, most patients given a CBD-THC tincture daily for three months ‘improved at least one of the core symptoms of ASD.’

Kuester is the Clinical Research Director at Fundación Daya, a Chilean nonprofit that promotes research into alternative medical treatments. Her poster reported that 21 patients (20 children and one adult) with ASD were treated with a daily dose of sublingual whole plant cannabis extracts (typically liquid 1:1 CBD:THC tinctures) for at least three months, between June 2016 and March 2017. No specific dosing information was included in the poster.

“Most cases improved at least one of the core symptoms of ASD,” Kuester reported, “including social communication, language, or repetitive behaviors. Additionally, sensory difficulties, food acceptance, feeding and sleep disorders, and/or seizures were improved in most cases.”

The oral extracts were well tolerated by most patients. Two patients exhibited more agitation, and one had more irritability, but those effects, Kuester wrote, were solved by changing the cannabis strain given to the patient.

The written record of that 2017 Chilean study can be found here.

Why Hasn’t It Been Studied More?

“I think it has a lot to do with children,” says neurologist Thomas Deuel. “It’s harder to study things in children than adults. Most of the epilepsy and cannabis studies have been with adults.”

“People are very particularly worried about affecting brain development in children with marijuana,” he adds.

Indeed, the American Academy of Pediatrics (AAP) officially opposes the legalization of cannabis—so much so that the organization recently reaffirmed its opposition in a press release.

Though it advocates for decriminalization, Seth D. Ammerman, MD, FAAP, a member of the AAP Committee on Substance Abuse, said: “We know marijuana can be very harmful to adolescent health and development. Making it more available to adults—even if restrictions are in place—will increase the access for teens. Just the campaigns to legalize marijuana can have the effect of persuading adolescents that marijuana is not dangerous, which can have a devastating impact on their lifelong health and development.”

Adding Autism as a Qualifying Condition

Over the past few years, advocates with MAMMA have successfully pushed lawmakers and state officials to add autism spectrum disorder (ASD) as a qualifying condition in states such as Pennsylvania, Minnesota, and Georgia. But Brandy Williams and other MAMMA activists haven’t yet broken through in Arizona.

Officials at the Arizona Department of Health Services, Williams said, considered her petition to include ASD “too broad.”

“ They keep referring to this evidence pyramid, and how studies are designed, and blah blah blah,” she said. “But even our pharmaceutical medications are not being held to the standards that they’re requiring to add a [medical cannabis] condition.”

Add in a dose of reefer madness, and you’ve got the perfect formula for no forward momentum. “We’ve already got Arizona Department of Health to admit that the reason why they don’t approve these petitions is because they do not want to give the public the perception that these government health regulatory agencies are proving these conditions and recommend the use of cannabis for those conditions,” Williams said.

The next Arizona Department of Health Services hearing on MAMMA’s petition is scheduled to take place in June.

Meanwhile, in Texas, the Lone Star State’s chapter of MAMMA (pictured below) lobbied members of the GOP at their annual state convention last week. The state party voted to not only expand the extremely limited Texas Compassionate Use Act, but also to decriminalize cannabis entirely.

Altering the ‘Attentional Spectrum’

Endocannabinoids can help regulate hunger, anxiety, neuronal excitability, protection and pain, among other things. With epilepsy, cannabidiol (CBD) can help suppress seizures. Those who look to cannabinoid medicine to help with autism believe that it can help bring order to a brain that’s a live wire.

“Kids with autism, adults with autism” says Deuel “have a lot of focus and attentional issues. They’re not clued into a lot of their surroundings, but they’re very clued into one thing that they kind of get obsessed about. So I think that when you give an autistic child cannabis, it alters their attentional spectrum.”

That—at least anecdotally—is what Brandy Williams and other parents who have administered cannabis to their ASD kids have noticed. For Williams’ son, Logan, cannabis did what 47 hours of weekly therapy couldn’t. She still recalls that first night with wonder. “He came up and he sat down next to me and watched a movie for the first time in his life.”