The results of a new study complicate the arguments of those promoting the benefits of marijuana legalization.
Those who view marijuana as a benign recreational drug have reason to reconsider their views in the aftermath of a study conducted jointly by the Northwestern University School of Medicine and Massachusetts General Hospital.
A study of a small group of 20 young people — ages 18 to 25 — revealed that casual use produced changes in brain chemistry that affect an individual's emotions and motivations.
Dr. Hans Breiter, one of the authors of the study, said more research will be necessary to confirm the results. But he said preliminary indications are that smoking marijuana "becomes a problem later on with prolonged use," specifically causing lack of focus and impairing judgment. The subjects of the study smoked marijuana four days a week, averaging 11 joints. Half smoked fewer than six joints a week.
Researchers conducted brain scans, comparing similar groups of users and non-users.
Researchers found that two areas of the brain — the amygdala and the nucleus accumbens — were different.
What this means is not clear. Perhaps these changes do not portend any long-term negative consequences. Then again, any changes in brain chemistry brought about by drug use are a warning sign of some kind.
One scientist from the University of Wisconsin-Milwaukee who has done separate research on marijuana use suggested that brain alterations occur "before you develop dependence." Another scientist suggested that the study's results indicate that marijuana use affects the brain earlier than was previously thought.
This preliminary study is potentially very important because a variety of states, including Illinois, are moderating their marijuana laws in a way that encourages use. Both Colorado and Washington have legalized marijuana. Other states, like California, have legalized so-called medical marijuana but have done so in a way that virtually anyone can get a prescription. Illinois is in the process of implementing what its backers contend is a strict medical marijuana law that will limit prescriptions to people with real afflictions. The direction, however, is unmistakable — legalization in one form or another on a broad scale.
The war on drugs has been a failure, and nowhere is that more obvious than in the high costs of prosecutions for marijuana consumption. Decriminalization would make more sense. But, as this study suggests, marijuana consumption carries its own set of risks, both to individuals and society as a whole.