Does Teen Marijuana Use Lead to Immune Damage in Adulthood?
Marijuana-Related Damage in Teens
Up-to-date figures compiled by the National Institute on Drug Abuse and the University of Michigan indicate that teens in the U.S. increasingly fail to perceive marijuana use as a health threat. However, a firmly established body of scientific evidence lays out the unique harms that teens are exposed to when they use this drug. For example, any given teenager who uses marijuana has an almost 100 percent higher chance of developing a diagnosable case of cannabis addiction than an adult who consumes the drug in similar amounts. The overall rate of addiction in teen marijuana users is roughly 17 percent; this figure does not isolate habitual users, who have much higher addiction risks. Heavy, regular marijuana consumption in adolescence can also interfere with the intricate and delicate course of normal brain development. In the short-term, this can translate into problems with memory formation, memory retention and logical thinking. In the long-term, altered brain development can translate into a partial, potentially permanent loss of overall intellectual ability.
Normal Immune Function
The human immune system is a complex, multi-part operation that relies on contributions from a range of body areas and tissue types, including bone marrow, your skin, the blood flowing through your arteries and veins, two organs called the spleen and thymus, your intestinal tract and your lymph nodes. When an invading microorganism or other type of threat enters your bloodstream, specialized cells from your immune system identify the invaders, tag them for destruction and carry out active attacks designed to reduce or eliminate the threat to your health. Problems with any portion of your immune system can potentially jeopardize your overall immune response. Researchers already know that the excessive consumption of several types of mind-altering substances, including alcohol, cocaine, opioid drugs and medications can substantially alter or outright damage your ability to respond to various sources of serious, potentially life-threatening infection in a timely, effective manner.
Impact of Early Marijuana Use
In the study published in the Journal of Leukocyte Biology, researchers from the University of Bologna and two other Italian institutions used laboratory experiments on mice to explore the potential impact of adolescent marijuana consumption on the health of the adult immune system. Some of the mice involved in the experiments were still in adolescence, while others had reached adulthood. For a period of 10 days, the researchers exposed both groups of mice to doses of THC (tetrahydrocannabinol), the substance in marijuana/cannabis mostly responsible for producing the drug’s mind-altering effects.
The researchers concluded that, after exposure to THC, both the adolescent and adult mice involved in the study underwent several changes in their immune function that signaled an overall decline in effective immune response. Within 50 days, the adult mice recovered from their THC exposure and experienced a restoration of their normal immune function. However, when the THC-exposed adolescent mice later reached adulthood, they continued to show ongoing signs of the immune system alteration that first appeared after THC was introduced.
Mice and other rodents often stand in for humans in drug testing that would be considered questionable or ethically objectionable in adults, teenagers or children. In their experiments, the researchers used doses of THC designed to approximate the level of THC exposure found in a person who uses heavy amounts of marijuana/cannabis. For this and other reasons, they believe their results likely reflect the immune system changes produced by the drug in at least some marijuana-using individuals in real-world circumstances. Based on their findings, the researchers believe that, while adult heavy marijuana users may recover their normal immune function if they halt their intake of the drug, adolescent heavy marijuana users may have long-lasting or potentially permanent immune system deficiencies, even if their drug intake does not continue in adulthood.
By: Gideon Hoyle