Adults only (18+)

This article explores what current studies reveal about the use of cannabidiol (CBD) in childhood epilepsy. It is written for parents and carers of children living with epilepsy, paediatric neurologists, and health care professionals seeking an accessible UK-centred summary of the evidence, regulatory context and practical considerations. The goal is to present clear, balanced information based on reliable UK sources, with a focus on safe use, realistic expectations and responsible messaging.

Introduction

If you are caring for a child who has epilepsy and you have come across discussions of CBD, you might be wondering what the research really shows. This article takes a look at the studies addressing CBD in childhood epilepsy, describes the kinds of epilepsy that have been investigated, summarises the outcomes, examines safety and regulatory issues in the UK context, and offers a view of how this fits into clinical practice. It is not intended as a recommendation for treatment, but rather as a grounded review of the evidence so that you and your child’s care team can have an informed conversation.

What is CBD and how has it been applied in childhood epilepsy

Cannabidiol, or CBD, is a chemical compound derived from the cannabis plant. Unlike THC (tetrahydrocannabinol) it is not psychoactive and has attracted interest for a range of potential neurological and non-neurological conditions. In the context of childhood epilepsy the interest centres on whether CBD can help children whose seizures are difficult to control by conventional treatments. In the UK a licensed CBD-based medicine is available for two rare syndromes in children, namely Dravet syndrome and Lennox-Gastaut syndrome. Research in these syndromes forms the core of what we know so far.

Which childhood epilepsies have been studied

The strongest research evidence for CBD in childhood epilepsy comes from two relatively rare syndromes. Dravet syndrome is a severe genetic epilepsy of early childhood, often starting in infancy, characterised by frequent febrile and afebrile seizures, developmental delay and comorbidities. Lennox-Gastaut syndrome is another severe, early-onset epilepsy disorder, characterised by multiple seizure types including drop attacks, learning difficulties and behavioural issues. Research has also begun in other epilepsy types and related conditions such as tuberous sclerosis complex. However the vast majority of childhood epilepsies have not been assessed in large randomised trials of CBD. UK paediatric guidance emphasises that outside these specific syndromes the evidence is much weaker.

What the randomised controlled trials show

In terms of high-quality evidence, there have been several double-blind randomised controlled trials of pharmaceutically-manufactured CBD in children and adolescents with Dravet or Lennox-Gastaut. These trials showed that children who received CBD experienced significantly greater seizure reduction than placebo in these syndromes. For instance, using a pure CBD formulation in children with Dravet, the seizure frequency was reduced compared to placebo. In children with Lennox-Gastaut, another study showed that CBD lowered the number of drop seizures. Observational and open-label studies also show reductions in seizures in children treated with CBD when standard treatments have failed. One UK centre reports that a child formulation without psychoactive elements reduced seizures by nearly 40 per cent in children with Dravet syndrome in trial conditions.

How large and how consistent are the effects

It is important to look at how meaningful these results are and how they should be interpreted in the context of the child and family. In the RCTs for Dravet and Lennox-Gastaut, reductions in seizure frequency often ranged in the order of around 30 to 50 per cent compared to placebo in some children. Open-label studies and real-world data show similar ranges of reduction though with greater variability. These figures mean that while many children experienced fewer seizures, not all achieved seizure freedom and responses varied considerably. Improvements were more evident in the specific syndromes studied than in broader epilepsy types. The evidence is strong in the specific syndromes but outside those contexts prescribing remains limited due to lack of data.

Mechanisms and scientific insights

Beyond clinical data, there is growing scientific interest in how CBD might work in seizure disorders in children. Studies have demonstrated that CBD can influence nerve signalling in regions of the brain involved in seizure activity. This kind of mechanistic data supports the notion that CBD is more than a speculative treatment and may act on identifiable pathways of neuronal excitability. However it is also true that mechanisms in animal or cellular studies do not always translate fully to clinical outcomes in children, especially given the diversity of epilepsy syndromes and developmental brain changes.

Safety, side-effects and interactions in children

As with any treatment in paediatrics it is essential to consider safety, tolerability and interaction with other medications. Although CBD has shown some efficacy in specific syndromes, there is limited long-term data on safety for children, especially regarding brain development, cognition and interaction with other anti-epileptic drugs. Side-effects reported in trials have included sedation, diarrhoea, appetite changes and elevated liver enzymes. Some children taking CBD alongside other AEDs such as clobazam or valproate may require more monitoring for liver function or other adverse events. The guidance further warns that unregulated CBD- or THC-containing oils bought from high-street or online often have inconsistent dosing, variable THC content and unknown long-term effects in children.

Regulation and UK context in paediatric prescribing

In the UK any preparation intended to treat disease must be authorised as a medicine. A CBD-based medicine with negligible THC has been approved for use in children with Dravet and Lennox-Gastaut. Paediatric neurology guidance states that such cannabis-based medicinal products should only be used in childhood epilepsy in defined circumstances when standard treatments have failed. Other forms of cannabidiol products are unlicensed in children and should not be assumed safe or effective. Until further trials expand the evidence base many children’s epilepsy services in the UK will reserve CBD for last-resort use under specialist care.

Limitations and knowledge gaps

Although the evidence for CBD in certain childhood epilepsy syndromes is growing, there remain significant gaps. Many epilepsy syndromes in children have not been studied in RCTs of CBD. Thus we do not know how widely the findings from Dravet and Lennox-Gastaut apply to other types of childhood epilepsy, whether developmental differences influence outcomes, or how long-term outcomes over years rather than months will behave. Another gap is the limited data on dose optimisation, the impact on cognition and development, and lack of studies in very young children or infants beyond the syndromes already studied. The presence of concurrent therapies complicates interpretation of results because in many trials CBD was given as an add-on to multiple AEDs. Moreover the quality of open-label or observational studies is lower than RCTs and may have bias.

Implications for clinical practice and families

For paediatric neurologists and epilepsy teams in the UK the current understanding is that CBD may be considered in childhood epilepsy under very specific conditions: when the child has a well-defined syndrome, when multiple standard treatments have failed, and when the treatment is managed in a specialist centre with full monitoring. Families should be aware that this is not a general therapy for all childhood epilepsies and that the benefits, though often meaningful, vary. Clinicians will monitor seizure frequency, side-effects, liver function, sedation, interactions with other AEDs and adjust accordingly. For families the key messages include: ensure the prescribing team is experienced, use only licensed pharmaceutical-grade CBD where indicated, maintain accurate seizure diaries, monitor for side-effects, and understand that non-licensed over-the-counter CBD oils are not equivalent and can carry risks.

What to ask your child’s epilepsy team

If you and your child’s care team are considering CBD for epilepsy the conversation might include how many other treatments have been tried to date, whether the child’s epilepsy fits one of the syndromes that have been studied, the formulation being proposed, what monitoring will be in place for side-effects and interactions, realistic goals of treatment, how response will be reviewed over time, and plans for longer term follow-up of development, cognition and school outcomes.

Future directions and ongoing research

Research in childhood epilepsy and CBD is continuing. New clinical trials involving children and young people with hard-to-treat epilepsy are underway to expand the evidence base, explore safety in different age groups and broader syndromes, and critically assess impact on learning, sleep, behaviour and quality of life, not just seizure counts. As knowledge grows it is possible that eligibility may widen, dosing may become better defined and long-term outcomes better characterised.

Conclusion

In conclusion the studies conducted to date provide meaningful evidence that in certain rare childhood epilepsy syndromes, pharmaceutical-grade CBD can reduce seizure frequency when used as an add-on therapy under specialist supervision. These results are promising for families facing very difficult-to-treat epilepsy. At the same time it is important to recognise the limitations: the evidence applies to specific syndromes, not all childhood epilepsy; long-term effects on the developing brain are still under study; and non-licensed products are not supported by the research. In the UK context the use of CBD in paediatric epilepsy remains a tightly regulated, specialist-only option, requiring careful consideration of safety, monitoring and realistic expectations. If you are exploring CBD for your child it is vital to engage your child’s epilepsy specialist team, ask the right questions, and proceed with clear, informed planning rather than ad hoc use.