(HealthDay News) – Exocannabinoids, such as the major psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC), interfere with the function of the endocannabinoid system, present in the developing central nervous system from conception onward.

Noting that the Δ9-THC content of modern marijuana has increased considerably, with some preparations containing up to 37.2% Δ9-THC, Delphine Psychoyos, PhD, from the Texas A&M Health Science Center in Houston, and K. Yaragudri Vinod, PhD, from the Nathan Kline Institute for Psychiatric Research in Orangeburg, NY, reviewed the potential effects of gestational exposure to Δ9-THC.

The researchers found that in utero exposure to Δ9-THC correlated with an elevated risk for anencephaly and neurobehavioral deficiencies in offspring, including learning disabilities, memory impairment, and attention-deficit/hyperactivity disorder. The developing central nervous system may be susceptible to Δ9-THC as well as other cannabimimetics, including the psychoactive ingredient of the Spice brand. These exocannabinoids interfere with the function of the endocannabinoid system, which has been established as being present from conception onward in the developing central nervous system, and is necessary for neuronal proliferation, migration, and differentiation.

“The argument that marijuana is a ‘harmless’ drug is no longer valid,” the authors write. “Although some of the cannabimimetics and constituents of marijuana appear to be useful in some conditions, the recent advances in registry and statistical evaluation of effects, which now take into account confounding variables, has enabled us to clearly affirm that marijuana is detrimental to pregnancy.”

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