This piece first appeared in Cannabis Now.
When researchers from the University of Pittsburgh Medical Center and Rutgers University set out to study the impacts of teen marijuana use, they expected to find results that echoed previous studies that suggested there was a connection between chronic teen use of cannabis and long-term health problems.
What they found instead was “a little surprising,” according to Jordan Bechtold, PhD, the lead researcher and a psychology research fellow at the University of Pittsburgh Medical Center. Their study, which observed 408 males from the late 1980s to 2009, found no links between chronic marijuana use as a teenager and a later development of cancer, depression, psychotic symptoms, asthma, anxiety or respiratory problems.
“There were no differences in any of the mental or physical health outcomes that we measured regardless of the amount or frequency of marijuana used during adolescence,” said Bechtold in a release.
The research was a small part of the larger Pittsburg Youth Study, which analyzed the health and social issues of Pittsburg public school children for 12 years. Each of the participants was asked to report their cannabis use, and were subsequently split into four groups: those who didn’t or barely smoked, those who were early chronic users, those who only smoked marijuana as adolescents and those who started smoking late in their teen years and continued to do so into adulthood. The different groups saw no marked difference in health issues as they aged.
The study also controlled for certain factors, such as cigarette smoking, the use of other illicit drugs and access to health insurance, that researchers thought could have influenced the findings. The results showed no difference in the findings between the different races and ethnicities involved in the study.
This is one of the few studies that have followed marijuana use in hundreds of participants for more than two decades of their lives, according to the release, as many other studies on the long-term health effects of teen cannabis use have only used data on a participant’s reported level of past usage.
“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.
Nevertheless, this study complicates beliefs about the dangers of teen use of marijuana that have long been held as scientific truth. And while some still put forth the argument that adult-use marijuana legalization will make pot more accessible to children and teenagers, another recent study found that teen marijuana use went down nationwide between 2011 and 2013.