Study: Teens who smoke weed daily are 60% less likely to complete high school than those who never use
THIS PIECE WAS SENT TO US BY AL ARSENAULT AND BRIAN SHIPPER, BOTH PRINCIPALS IN THE ODD SQUAD. MANY THANKS.
Pre-rolled marijuana joints are pictured at the Sea of Green Farms in Seattle, Washington June 30, 2014. REUTERS/Jason Redmond
Teenagers
who smoke marijuana daily are over 60 percent less likely to complete
high school than those who never use. They're also 60 percent less
likely to graduate college and seven times more likely to
attempt suicide. Those are the startling conclusions of
a new study of adolescent cannabis use out today in The Lancet Psychiatry, a British journal of health research.
Researchers
gathered data on the frequency of cannabis use among 3,725 students
from Australia and New Zealand, and then looked at the students'
developmental outcomes up to the age of 30. They found "clear and
consistent associations between frequency of cannabis use during
adolescence and most young adult outcomes investigated, even after
controlling for 53 potential confounding factors including age, sex,
ethnicity, socioeconomic status, use of other drugs, and mental
illness."
Significantly, they found that the risks for negative
outcomes increased with the frequency of cannabis use. In a conference
call, study co-author Edmund Sillins said that the relationship between
cannabis use and negative outcomes is significant even at low levels of
use (e.g., less than monthly), and that "the results suggest that there
may not be a threshold where use can be deemed safe" for teens.
According to the study, there are
significant relationships between cannabis use and high school
graduation, college graduation, suicide attempts, cannabis dependency
(not wholly surprising), and other illicit drug use.
The chart
plots the odds ratios of the frequency of cannabis use on various
outcomes, compared to not using cannabis at all. A value of 1 would
indicate equal odds of a given outcome, 2 would indicate an outcome
twice as likely as you'd get from not using cannabis at all, and a value
less than 1 would indicate decreased odds of a given outcome.
So
for instance, a person who uses cannabis less than monthly would have
slightly lower odds of graduating high school or getting a college
degree, compared to a person who doesn't use at all. Increased use
further decreases this likelihood. On the other hand, a person who uses
cannabis monthly would have roughly 4 times the likelihood of becoming
dependent on cannabis as a person who doesn't use at all.
It's
worth noting that for many of these indicators, the confidence intervals
(error bars on the chart) are fairly broad, meaning that there's some
degree of imprecision in these numbers.
You
can expect these findings to be highly cited by opponents of
liberalized marijuana laws, like the Office of National Drug Control
Policy and the Smart Approaches to Marijuana project. But it's important
to put them in proper context.
First, the causality isn't 100
percent clear. The researchers did a fantastic job of trying to account
for a number of confounding factors. But particularly when it comes to
the educational outcomes, there are a lot of factors at play. For
instance, if a teacher knows or even suspects that a certain kid is
using drugs, that may predispose the teacher against that student.
"Teachers are very likely to stigmatize drug users," says Joseph
Palamar, co-author of
another recent study comparing teen marijuana and alcohol use. "That stereotype gives kids problems, and that kid's not gonna want to go to class."
Palamar
also says that because marijuana "is an illegal drug, you have to buy
it in an illegal manner, and then you’re exposed to the black market.
Marijuana use is affiliating you with other kids, some of whom might be
problematic – people more likely to question authority. You become
affiliated with things that might have a negative impact on your
education."
Moreover, Palamar's research shows that because of
marijuana's legal status, teen cannabis users are much more likely to
get into trouble with the police than teen alcohol users. And in many
cases, if you have a drug conviction on your record, you become
ineligible for college aid. "If you get caught with drugs, you're not
able to go to college," he told me.
In other words, many of the problems associated with teen cannabis use are likely a function of the drug's illegal status.
That
said, it's completely reasonable to accept that heavy use of any drug
as a teenager - be it weed, alcohol, or tobacco - is going to lead to
negative consequences down the line. This in itself isn't an argument
for prohibition of cannabis. For that, you'd need to demonstrate a link
between relaxed cannabis laws and increased teen drug use, with the
negative social consequences that go along with it. But
multiple studies have shown a flat or even negative relationship between medical marijuana laws and teen cannabis use, for instance. And
very early data out of Colorado shows a slight dip in teen use since the state passed a legalization measure in 2012.
But
the study does lend strong support to the case for efforts to keep the
drug out of the hands of teens, and it does make a case for closely
monitoring adolescent marijuana use in states that do legalize it.
Thinking
more broadly about the effects of drug prohibition, you have to weigh
the consequences of teen drug use against the societal consequences of
failed drug war policies - skyrocketing incarceration rates and
countless families and communities decimated by the illegal drug trade
and its overzealous opponents.
