A new study that aimed to assess how people living with autism spectrum disorder (ASD) could benefit from medical cannabis has discovered positive results, with improvements observed across multiple measures over an 18-month period.
Published in the journal Neuropsychopharmacology Reports, the research highlights how treatment with cannabis flowers, cannabis oils, or a combination of both was associated with meaningful and beneficial outcomes across multiple metrics.
Scientists from the Medical Cannabis Research Group at Imperial College, London, conducted the trial. The data was supplied by 130 patients who had been diagnosed with ASD, were already being treated with cannabis medicine, and who were registered on the UK Medical Cannabis Register (UKMCR).
Patients were assessed at the beginning of the study and at regular intervals over an 18-month period. The results showed that they experienced significant improvements in areas including quality of life, anxiety, and sleep.
ASD is a neurodevelopmental disorder that is marked by challenges in social communication and interaction, alongside restricted and repeated behaviours. Patients can experience different symptoms, including but not limited to social communication and interaction difficulties, oversensitivity, being fixated on specific subjects and repeated behaviour patterns.
There are currently no recognised pharmaceutical treatments for ASD, although people living with the condition are often prescribed drugs such as antidepressants and stimulants for co-occurring conditions including ADHD and depression.
The treatments available for ASD are usually focused on the individual patient’s needs and rely heavily on therapy-based interventions that include behavioural, speech and language, and occupational therapies.
It is estimated that around 0.6% of the global population lives with ASD, and with the recent advancements in diagnosis techniques, such as the use of AI to scan facial expressions, this figure is rising.
People living with ASD are highly likely to experience other conditions alongside autism. Between 50 – 83% of people with ASD are thought to have to learn to cope with symptoms that often exacerbate their condition, including anxiety, sleep disorders, and depression.
Researchers on the study were not looking at cannabis as a cure or treatment for ASD itself, but rather an alternative treatment for the co-morbid conditions which often accompany it. Currently, many patients are prescribed drugs such as SSRIs and antipsychotics, which can cause unwanted side effects and are often poorly tolerated.
“ASD treatment does not seek to change the core features of the condition, but rather treat associated distressed behaviours or psychiatric conditions. There is a paucity of high-quality evidence on the efficacy of these therapies in ASD. Conventional pharmaceutical treatments may include selective serotonin reuptake inhibitors and atypical antipsychotics, such as risperidone and aripiprazole, which have shown to reduce some dimensions of symptoms associated with ASD,” the authors said.
To test the efficacy of cannabis for the treatment of co-occurring ASD symptoms, researchers assessed 130 patients who were living with ASD and who were registered on the UKMCR.
Participants completed an initial assessment at the beginning of the study in which they supplied details about their tobacco and alcohol use, cannabis status (if they used, didn’t use, or used to use it), amount of grey-market cannabis used and details about their current cannabis prescription. They were also asked to complete patient-reported outcome measures (PROMs), which would evaluate their general anxiety level, sleep, and quality of life score, and asked to provide details on how their condition has changed (PGIC).
Across all recorded measures, patients’ scores were observed to increase from baseline all the way through to 18 months, apart from the PGIC score, which showed improvements from 1 month through to 18 months.
From the cohort, 25 participants reported adverse events (AEs), with most being classified as either mild or moderate. The most common adverse events were insomnia, dry mouth and lethargy.
Notably, the median daily THC dose increased nearly tenfold during the study period, from 20mg/day at baseline to 192.25mg/day at 18 months, suggesting dose escalation was required to maintain effects.
Researchers noted that cannabis medicine had a positive effect on the co-occurring symptoms experienced by participants in this study, but acknowledged the study’s limitations due to the lack of a control group.
“This case series explored the outcomes of autistic adults treated with CBMPs. The findings indicate that CBMPs were associated with improvements in anxiety, sleep quality, and health-related quality of life,” the authors said in their conclusion. “While a proportion (19.23%) of the cohort reported adverse events, the majority were mild or moderate. As an uncontrolled observational analysis, the study cannot establish causation; reported changes should be interpreted as temporal associations and not as evidence of a treatment effect.”
The findings add weight to those of other studies investigating how cannabis medicines can be used to assist those living with ASD, with results suggesting that it can be used for short-term relief and advising against long-term reliance on cannabis.