Studies have shown that several adults diagnosed with Attention-deficit/hyperactivity disorder (ADHD) self-medicate with cannabis products, either in addition to or as a preferred method to traditional ADHD medications. However, in clinical practice medical cannabis is not commonly used in the UK or in other countries. The anecdotal reports of people with ADHD who self-medicate has prompted further research into medical cannabis, cannabidiol (CBD), and tetrahydrocannabinol (THC) used for ADHD.
What is ADHD?
ADHD is one of the most common neurodevelopment disorders, with most cases being diagnosed during childhood. Characteristic ADHD symptoms include decreased attention, hyperactivity, and impulsive behaviour. Learn more about ADHD here.
What is ADHD in children
ADHD is thought to affect around 5% of children, and those who are diagnosed with ADHD often show signs from an early age, which can become more noticeable as a child’s circumstances change, such as starting school. Other indicators can include, struggling to focus during education and facing social difficulties with family and friends, however, the most common signs of ADHD include fidgeting, lack of concentration, and restlessness. These can also be common in children without ADHD and therefore it is important a diagnosis is made by an appropriately trained professional.
What is ADHD in adults?
ADHD disorder affects 2.5% of adults globally. Although the causes of ADHD are not completely understood, it is widely believed that both genetics and environmental factors can play a part in its development. ADHD must be present in childhood or adolescence, however, increased awareness and changes to diagnostic criteria has seen an increasing number of adults being diagnosed with the condition for the first time.
What medication is used for ADHD?
Treatment options for ADHD include both medications and talking therapies. Medications for ADHD can typically be split into two classes. The first group of medications are known as stimulants, which act to increase the action of dopamine in the brain. Non-stimulant medications work by targeting the sympathetic nervous system, which is involved in the ‘fight or flight response’ to stress.
ADHD medication and cannabis
There are a growing number of anecdotal claims made about the effect of cannabis in individuals with ADHD. In 2017, a study published by European Neuropsychopharmacology set out to further examine these effects using a placebo-controlled trial, which recruited 30 participants.
Over a six-week period, the participants were given Sativex – a preparation of cannabinoids that contains a 1:1 ratio of THC or CBD for ADHD, or a placebo.
Cognitive performance and activity level (head movements) were measured using the Quantitative Behavioural Test (Qb Test) after dosing of each treatment. These results were compared with the baseline results (prior to the start of either treatment) throughout the duration of the study.
Cannabis for ADHD symptoms: the results
Throughout the study period, a small number of participants, in both the active and placebo groups, experienced adverse events. One participant of the active (Sativex) treatment group withdrew from the trial following the onset of muscular spasms/seizures. This was treated as a serious adverse event, though the reaction has not been reported in previous Sativex studies.
Three more participants of the active group experienced mild adverse side effects during treatment. These side effects included light-headedness and diarrhoea and resolved within a few days allowing for continuation with the trial. A final participant in the placebo group experienced an increased heart rate, the cause of which was not identified.
The results of the trial also showed that the active groups receiving the medical cannabis product Sativex experienced a significant change in hyperactivity/impulsivity, and a cognitive measure of inhibition.
However, no significant difference in cognitive performance and activity levels was found between groups according to the Qb Test score.
Whilst the results from this study provide promise, it is important to recognise that the scope of this study is small with a limited number of participants. However, it does highlight the need for further studies in the form of randomised controlled trials and real-world evidence collection. These will be necessary to determine the positive effects of cannabis on ADHD, in addition to the safety of its wider utilisation.
