Uncertainties of Medical Marijuana Make it Unsafe for Children

No current evidence-based medicine is available to support prescribing of medical marijuana for children.

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Seth Ammerman, M.D. is a clinical professor of Pediatrics at Stanford University, Lucille Packard Children's Hospital

Pediatricians are sympathetic to parents who have a child with a chronic or debilitating illness that is not adequately treated by usual medical care, and understand that parents often look for alternatives that may be helpful. However, there are significant problems with recommending medical marijuana for children and adolescents.

Medical marijuana refers both to the cannabis plant and to biologically active compounds called cannabinoids, which regulate a number of functions in the human body, including the nervous system, the immune system, and various brain functions like understanding and memory. We do not know the exact way in which medical marijuana affects these functions. We do know that humans produce "endocannabinoids " and we think medical marijuana may have a similar effect on the body as these naturally occurring compounds.

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Cannabinoids called tetrahydrocannabinol (THC) and cannabidiol (CBD) may have therapeutic benefits. However, finding the proper dosage for maximum therapeutic benefit and least risk of side effects is problematic. THC and CBD levels may vary greatly from plant to plant, which makes accurate dosing difficult.

Most marijuana products sold at dispensaries are not tested for cannabinoid content, so the purity and actual dose based on THC or CBD content is usually unknown. Patients often need to try different preparations and doses to find one that will help with the symptoms being treated. Additionally, given that over 200 cannabinoids have been identified in the marijuana plant, it is unclear which other ones or combinations may be therapeutically beneficial. This makes duplication of good outcomes impossible. It also makes it impossible to provide adequate warning against side effects, which will vary with dosage and any combinations.

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Anecdotal reports of successful treatment for a specific problem in a particular individual do not necessarily project to a broader population. Patients may respond differently to and experience different side effects from the same medication. For example, medical marijuana has been reported to help with, but also cause, anxiety and depression.

Furthermore, there is no known pediatric dosing for any medical marijuana product. Thus using medical marijuana in pediatric and adolescent populations is completely trial and error. Additionally, it is unknown what, if any, long-term effects and side effects occur in pediatric and adolescent populations. Cognitive impairment is of special concern. New research in brain development found that brain maturation isn't completed until the early to mid-20s. The developing brain of a child is often more vulnerable to exposure to compounds than that of an adult.

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Finally, the younger an adolescent starts using substances, whether tobacco, alcohol, or other drugs including marijuana, the more likely they are to develop dependence on, or addiction to, that substance. Brain imaging studies in adolescents demonstrate that use of substances, including marijuana, may alter the developing brain itself. The significance of these changes is not fully understood, but is clearly not normal.

At this time, no current evidence-based medicine is available to support prescribing of medical marijuana for children and adolescents. Food and Drug Administration-sponsored research would be a step in clarifying the role of cannabinoids in potential treatment of a variety of diseases.