Article Text
Abstract
Aims Attention deficit Hyperactivity Disorder (ADHD) is the commonest neurobehavioural disorder diagnosed in childhood with a chronic course extending into adulthood in at least a third of the patients. There are ongoing controversies about the safety and efficacy of chronic use of CBD in children and adults.
We aimed to identify best evidence from published literature for effectiveness of cannabinoid products in controlling symptoms of ADHD and its associated common co-morbidities.
Methods We systematically searched several health and social science databasses for relevant published articles using keywords including ‘Attention Deficit Hyperactivity Disorder’, ‘ADHD’, ‘Disruptive Behaviour Disorders’, ‘cannabinoids’, ‘cannabidiol’, ‘cannabi*’ and ‘CBD’.
Results 7/11 relevant papers were related to adults while 4 were about children and young people (CYP) with ADHD. There is a dose-related association between chronic heavy regular use of cannabis and ADHD symptoms in adults. This is likely due to many adult ADHD patient self-medicating with cannabis. Chronic abuse of Cannabis is associated with abuse of other substances, including ecstasy (MDMA) and methamphetamines.
Limited RCT against placebo showed positive effect of CBD in improving core ADHD symptoms among adults over a 6 week period with no negative effect on cognitive function. Limited study of CBD-based medicines, given as adjunct to pharmaco- and psychotherapy, suggest promising improvement in the symptoms of ADHD and many co-morbid mental, social, communication, behavioral and motor disorders in adults.
The dearth of research evidence among CYP as well as the knowledge of significant differences between the level of maturation and plasticity of the adolescent brain makes it impossible to extrapolate any beneficial effect of CBD use in adults to adolescents and younger children for management of ADHD and its common comorbidities.
Conclusion There is insufficient research evidence to support recommendation of CBD products in CYP for ADHD management in both children and adults. Positive effects of CBD on ADHD and other MH disorders have been found in short-term studies but more chronic CBD abuse has often been associated with detrimental effects on cognitive functioning, educational achievement and employment prospects.