Bad news, everyone: smoking too much pot as a teen could permanently lower your IQ

Smoking too much pot as a teen could permanently lower your IQ

by Robert T. Gonzalez

One of the most thorough studies of its kind has concluded that smoking too much reefer as a teenager is linked to significant cognitive decline. More frightening still: the effects could be permanent. Here’s everything you need to know about the study’s findings.

Here’s the gist: The study followed 1,037 New Zealanders from birth through age 38, monitoring their IQs and marijuana usage throughout. IQ tests were administered first at age 13 (before the test subjects had started smoking pot), and again at 38, “after a a pattern of persistent cannabis use had developed.”

The findings reveal that test subjects who smoked heavily throughout adolescence suffered an average drop of eight points in their IQ scores. According to Madeline H. Meier, first author of the study, this impairment was most prevalent among adolescent-onset cannabis users:

Adolescent onset users, who diagnosed with cannabis dependence before age 18, tended to become more persistent users, but… after equating adolescent- and adult-onset cannabis users on total number of cannabis-dependence diagnoses, adolescent-onset users showed greater IQ decline than adult-onset cannabis users. In fact, adult-onset cannabis users did not appear to experience IQ decline as a function of persistent cannabis use. [emphasis added]

Effects of persistent, early-onset cannabis use also appear to be global, meaning they were detectable across a variety of mental functions ranging from processing speed to verbal comprehension and working memory. Test subjects also nominated people “who knew them well” to complete questionnaires relating to problems with their attention and memory. The researchers write that “informants reported observing significantly more attention and memory problems among those with more persistent cannabis dependence.” Perhaps most unsettling of all, however, is the observation that the cognitive decline appears to be permanent; “cessation of cannabis use,” note the researchers, “did not fully restore neuropsychological functioning among adolescent-onset cannabis users.” (A glimmer of hope: previous studies indicate that cognitive recovery is possible after quitting weed.)

There are several things that make this study noteworthy. For instance, following test subjects over the course of four decades allowed Meier and her colleagues to gauge participants’ cognitive abilities before they started smoking weed. The researchers claim this allowed them to rule out pre-existing neuropsychological impairment as an explanation for the link between early-onset marijuana use and subsequent cognitive decline. In other words: if a causative relationship exists between weed and cognitive impairment, it appears to be the pot-use that’s begetting the impairment, not the other way around.

It’s important to point out, by the way, that at no point do the researchers say that early-onset marijuana use causes cognitive decline. As Meier and her colleagues explicitly state: “our data
cannot definitively attest to whether this association is causal,” nor can it “reveal the
mechanism underlying the association between persistent cannabis dependence and neuropsychological decline.” In other words, we’re still dealing in terms of correlation, here. Having said that, the study does go a long way in ruling out a number of alternative explanations that have confounded the results of similar studies linking cannabis and cognitive decline in the past, including hard-drug and alcohol dependence, and the years of education received by users versus non-users.

The biggest question raised by this study — how much pot is too much? — points to its limitations. Reports of drug-use in the study were self-reported, which, unlike biological assays (a urine test, for example), are inherently subjective.

But the question of “how much” is arguable less important than “when,” or “what age?” The fact that cognitive impairment was detected in adolescent-onset smokers and not adult-onset smokers is highly suggestive that weed has a neurotoxic effect on the developing adolescent brain (what Meier and her colleagues refer to as the “developmental vulnerability hypothesis”), a conclusion that gels with a number of previous studies.

“Puberty is a period of critical brain development, characterized by neuronal maturation and rearrangement processes and the maturation of neurotransmitter systems (e.g., the endogenous cannabinoid system),” conclude the researchers, “making the pubertal brain vulnerable to toxic insult.” They continue:

Prevention and policy efforts should focus on delivering to the public the message that cannabis use during adolescence can have harmful effects on neuropsychological functioning, delaying the onset of cannabis use at least until adulthood, and encouraging cessation of cannabis use particularly for those who began using cannabis in adolescence.

The researchers’ findings are published in the latest issue ofProceedings of the National Academy of Science.


The Neil Armstrong Era: Boldly Going Where No One Went Before

The Neil Armstrong Era: Boldly Going Where No One Went Before

by Howard Barbanel

A genuine piece of America passed away on Saturday. The man who really, truly boldly went where no man had gone before — Neil Armstrong, the first human being ever to leave the confines of Earth and set foot on any extraterrestrial body (that being the moon) was gathered up for one last voyage to the stars and beyond.

Interestingly and coincidentally, I was at a dinner with a large group on Friday evening where some of the younger people in attendance brought up the subject of whether man had ever in fact landed on the moon. The various Hollywood sound stage conspiracy theories ricocheted across the room when I felt compelled to inform those born after the 1970s that, like 600 million people in July 1969, I was a witness to history.

I was an 11 -ear-old camper at a place called Camp Equinunk in rural Wayne County, Pennsylvania and they had a hotel atop a hill where parents would stay when visiting. This hotel had a big dining room and a large (well, for that time) 25-inch tube-fired TV which was wheeled in and about 100 of us got to watch the moon landing in real time in living black and white. There are nutty revisionists and deniers who feel the whole thing (and subsequent moon landings) were completely contrived, but I know what I saw.

As a kid, to me it seemed that America in 1969 was a magical place of infinite possibilities. Aside from the moon landing, what could be more improbable than the expansion New York Mets winning the World Series or the expansion AFL New York Jets winning the Super Bowl? It was a time of Captain Kirk and Mr. Spock on NBC, Larry Hagman as Major Anthony Nelson as the bemused astronaut on I Dream of Jeannie, Dr. Smith mucking things up in Lost in Space and Charlton Heston battling for the dignity of humanity in the first Planet of the Apes movie, which I saw for the first time that summer while lying on a blanket in the social hall of the aforementioned sleep away camp.

To paraphrase Tom Wolfe, America to us kids at that time seemed like a “country in full.” Yes, the Vietnam War was raging but this concerned people seven to 10 years older than me and the other kids playing ball out in the street in front of our houses. We were busy living never-ending “Pleasant Valley Sundays,” riding our Schwinn Stingrays to the candy store. Our parents drove Pontiacs and Oldsmobiles in snot green or dark orange with black vinyl tops. A slice of pizza was a quarter and you could get an ice cream pop for ten to 15 cents. We collected 45 RPM “singles,” the way people download one song at a time now to their MP3 players and phones. There were but a few television stations, no way to record shows and we tended to live more of our lives in real time than it seems we do today.

In the ’60s we had JFK urging us to land a man on the moon “in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.” It was a time of LBJ prodding America towards civil rights and equality for all its citizens. It was a time of almost unparalleled economic prosperity and opportunity where we as a country dreamed big dreams and actually fulfilled a good many of them.

Neil Armstrong was the physical embodiment of the metaphors for Americans in the ’60s. He was handsome, heroic, modest and self-effacing. He was a man of few words and great deeds and those few words, “one small step for man, one giant leap for mankind” in a sense were the preamble for the age of high technology that the space race ushered in, to a point where we now hold in our hands everyday the kind of gadgets that we used to see imagined on TV and in the movies.

Armstrong was the “all-American boy,” the paradigm for what so many of us then young boys aspired to be regardless of our backgrounds, ethnicity or science skills.

Armstrong represented an America of really big dreams and of infinite possibility. Today, what passes for discourse in this country? Celebrity divorces? Politicians vilifying and dehumanizing one another over the relative merits of the federal budget?

For that kid sitting cross-legged on the floor that July evening in 1969 it seemed as though there was nothing America couldn’t do. Simon and Garfunkel asked “where have you gone Joe DiMaggio?” For us in our time, it might very well be “where have you gone Neil Armstrong?” We hope he’s looking down on us from that big lunar module in the sky and puts in a good word for America with celestial “mission control,” because if our country deserves blessings going forward it’s in part due to the kind of people we’ve produced like Neil Armstrong.