Use of Marijuana: Effect on Brain Health: A Scientific Statement From the American Heart Association

Abstract

Marijuana is perceived as a harmless drug, and its recreational use has gained popularity among young individuals. The concentration of active ingredients in recreational formulations has gradually increased over time, and high-potency illicit cannabinomimetics have become available. Thus, the consumption of cannabis in the general population is rising. Data from preclinical models demonstrate that cannabinoid receptors are expressed in high density in areas involved in cognition and behavior, particularly during periods of active neurodevelopment and maturation. In addition, growing evidence highlights the role of endogenous cannabinoid pathways in the regulation of neurotransmitter release, synaptic plasticity, and neurodevelopment. In animal models, exogenous cannabinoids disrupt these important processes and lead to cognitive and behavioral abnormalities. These data correlate with the higher risk of cognitive impairment reported in some observational studies done in humans. It is unclear whether the effect of cannabis on cognition reverts after abstinence. However, this evidence, along with the increased risk of stroke reported in marijuana users, raises concerns about its potential long-term effects on cognitive function. This scientific statement reviews the safety of cannabis use from the perspective of brain health, describes mechanistically how cannabis may cause cognitive dysfunction, and advocates for a more informed health care worker and consumer about the potential for cannabis to adversely affect the brain.

Medical marijuana: what are we talking about?

“…Of these users, 10% can be considered dependent. The 18% increase in marijuana users among the global population during the last decade 4 is another alarming fact that concerns and challenges public mental health policy and drug enforcement. 3 , 4 …”

“…Delta-9-tetrahydrocannabinol (THC) is the main cannabinoid responsible for the psychoactive effect of cannabis, and its action is associated with impaired learning, memory, attention, and motor coordination. 2 , 4 Adverse effects of cannabis, such as psychosis, seems to be dependent on the THC dose imparted, 2 although this remains a point of academic debate. 4 …”

“… 2 , 4 Adverse effects of cannabis, such as psychosis, seems to be dependent on the THC dose imparted, 2 although this remains a point of academic debate. 4 …”

“…3 Public policies should focus on raising awareness about the potentially harmful effects associated with the use of marijuana by the general population. 4 Possible strategies include the use of standardized concentrations of active biological compounds and increase health warnings on available formulations. 4 Also, higher investments in scientific research to investigate harmful health effects of the non-medical use of marijuana are needed, as well as a better definition of the health conditions in which products derived from cannabis can be employed as an effective treatment.…”

“…Marijuana is considered a harmless drug, and its recreational use has gained popularity among young people. 4 In some parts of the world, products derived from cannabis have also become more potent. 4 , 5 …”