Treatment with medical cannabis may be effective for patients with attention deficit/hyperactivity disorder (ADHD).
A team of British researchers from the Institute of Psychiatry, Psychology and Neuroscience, King’s College London conducted a randomized, placebo-controlled, double-blind study on this issue. The efficacy of a cannabinoid medication, a Sativex mouth spray, was studied in 30 patients with ADHD. The oral spray was a mixture of the main constituents of the cannabis plant, tetrahydrocannabinol and cannabidiol. The ratio was 1:1. Patients were divided into a test and a control group: 15 patients with ADHD received the Sativex mouth spray (test group) and 15 patients with ADHD received a placebo (control group, placebo-controlled study design). Neither the patients themselves nor the researchers knew which group a patient belonged to (double-blind design). The Sativex oral spray and the placebo did not differ in appearance, taste, or dosage form. Patients were randomly assigned to the two groups, i.e., the study design was randomized. The efficacy of medical cannabis was evaluated on cognitive performance, activity level, behavioral symptoms of ADHD, and emotional dysregulation after 6 weeks.
Results of the study on the efficacy of cannabinoids in ADHD
The research team led by Ruth Cooper was able to show that treatment with the Sativex oral spray led to a significant improvement in hyperactivity and impulsivity. No differences in cognitive performance were observed between the control and experimental groups. A trend could be observed regarding an improvement in inattention and mood swings – however, the effects between the groups were not statistically significant.
In this study, treatment with medical cannabis showed a improvement in ADHD symptomatology without cognitive impairment.
To control for potential side effects, the medication was gradually increased over the 2-week period to the maximum dose of 14 spray strokes per day (an average of 5 strokes per day was used). Side effects observed included dizziness when more than one spray was taken at a time and lasted for a few hours.
Overall, this pilot experimental study provides preliminary evidence of the efficacy of Sativex in adult patients with ADHD.