Health

It Turns out the Worst Rumors About Marijuana Are Dead Wrong

August 5th 2015

Researchers have come to some remarkable conclusions about the effects of marijuana use in recent years—how it reduces pain and helps heal fractured bones—but surely long-term use poses health concerns, right? Not really, says Jordan Bechtold, the lead researcher behind a new study on chronic adolescent use of cannabis.

Published in the journal Psychology of Addictive Behavior this month, the study looked at how long-term marijuana use affected teenage boys—physically and psychologically—and determined that the risks commonly attributed to chronic users are essentially unfounded. No, smoking a lot of pot over a long timespan does not, as others have argued, lead to depression, psychosis, lung cancer, asthma, or heart problems.

"I think we were most surprised that the prevalence of mental health disorders was not elevated among the chronic high marijuana users," Bechtold told ATTN:. "This was surprising because mental health problems are often more common among heavy substance users and individuals with substance use disorders, even if they are not a causal factor in the development of these disorders or a direct consequence of substance use."

The team of psychologists from the University of Pittsburgh Medical Center surveyed participants involved in a research project known as the Pittsburgh Youth Study, which started tracking 14-year-old male public school students in the late 1980s in order to analyze social and health effects. "For 12 years, participants were surveyed annually or semiannually, and a follow-up survey was conducted with 408 participants in 2009-10 when they were 36 years old," the American Psychological Association wrote.

Given the backlog of opposing studies on chronic marijuana use, these researchers aimed to inform the national debate on marijuana legalization by offering up comprehensive information on a wide range of long-term effects of cannabis use. They sorted through previous research on the subject, identified patterns in the claims of health professionals, and sought to either validate or debunk them.

"This study is part of a larger program of work focused on understanding the short-term and long-term effects of regular marijuana use," Bechtold added. "Other researchers have found that marijuana users have more behavioral and/or health problems than low or nonusers, but this is likely due in part to other factors that differ between users and nonusers (e.g., predisposition toward depression, tobacco use), and not marijuana use per se."

Bechtold continued:

"This is starting to ring true in some of our other work examining the potential long-term outcomes associated with chronic marijuana use, such as criminal offending and occupational functioning."

In short, they debunked many of the myths associated with the physical and mental effects of long-term marijuana use. Marijuana does not increase your risk of developing lung cancer; it does not seem to cause respiratory problems such as asthma; it does not make you more likely to experience adverse cardiovascular events (i.e. heart attacks); it does not appear to have any connection to future metal health issues—not psychosis, anxiety, or depression; it is, in general, a low-risk substance that has been inaccurately depicted by critics as a dangerous drug.

"Overall, data from this sample provide little to no evidence to suggest that patterns of marijuana use from adolescence to young adulthood, for the Black and White young men in the present study, were negatively related to the indicators of physical or mental health studied here," the study concluded. And while the researchers do not discredit earlier studies on the subject, they acknowledged that the findings for now only apply to men. They reached no conclusions about the effects of chronic marijuana use for women.

“We wanted to help inform the debate about legalization of marijuana, but it’s a very complicated issue and one study should not be taken in isolation,” Bechtold said.

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