Dear Doctor: Marijuana seems to be increasingly accepted in our country. But I worry about my kids using it. Is it addictive?
Dear Reader: You're right to be worried -- and not only because marijuana can indeed be addictive.
Marijuana has gained greater acceptance in this country, not in small part because its medical use can stimulate appetite, control nausea and control pain. One potential problem with this degree of acceptance is how adolescents view the drug.
In 2015, 70 percent of high school seniors viewed marijuana as not harmful, according to the National Institute on Drug Abuse's (NIDA) Monitoring the Future survey; in 1990, only 20 percent felt this way. Interestingly enough, the 2015 survey also found that 70 percent of 12th-graders disapprove of the regular use of marijuana.
Perhaps the biggest risk with marijuana is how it affects the adolescent brain. The endocannabinoid system, a vast system of receptors within the brain, spinal cord and smaller nerves, affects multiple brain and body functions. This system continues to develop in humans until the age of 21 or so.
If used frequently in adolescence, marijuana can rewire many of these nerve pathways. These changes aren't seen as much in the adult brain and, if they surface, can be easily reversed by stopping use. In adolescents, however, this rewiring of the nervous system may create addiction.
According to the NIDA, only 9 percent of people who try marijuana become addicted. However, this number increases to 16 percent among those who start using marijuana in adolescence. It increases further if marijuana is used daily in adolescence. In fact, 17 percent of admissions to publicly funded substance abuse programs are related to marijuana.
Some of my patients argue that alcohol is a much more addictive substance and can cause withdrawal symptoms that are life threatening. That is true. However, just because one substance has particularly bad effects doesn't mean another one is safe. There are problems with each.
Marijuana not only causes short-term memory loss, it also affects mental abilities for days after its use. That means a person's ability to plan, organize, solve problems and make decisions is impaired, which has significant ramifications for adolescents trying to retain information learned in school or trying to maintain good study habits.
Further, for those predisposed to schizophrenia, marijuana can induce psychosis and, in younger users, can decrease the age of schizophrenia's onset. People with a familial predisposition to schizophrenia should certainly avoid use.
However, marijuana has not been associated with depression or bipolar disorder, and while those with generalized anxiety are more likely to use marijuana, that connection may be linked more to a need to compensate than to causal effect.
I would advise high school students not to use alcohol or marijuana in adolescence, but the reality is that your child, like many others, may be exposed to these and other drugs in high school. As a parent, be sure to watch for signs of abuse or consistent use, and to note any psychological issues that could lead to frequent marijuana use.
With the greater acceptance of marijuana within our society, increased exposure and the likelihood of abuse are rising. Guide your teenager to hobbies, sports, outdoor activities or simply reading a book as a way to cope with the stressors of high school life. And, above all, keep an open line of communication.
(Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.)
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