Generations of parental warnings may not be wrong: A massive study of available data finds that teens who use marijuana have significantly worse outcomes at school. Data from 63 studies involving almost 440,000 youths found "cannabis use during adolescence is probably associated with lower school grades; less likelihood of high school completion, university enrollment and post-secondary degree attainment; and increased school dropout rate and school absenteeism," according to Canadian researchers. The study was led by Li Wang, of McMaster University in Hamilton, Ontario, and published Oct.
7 in the journal JAMA Pediatrics . As the research team noted, one 2019 study found more than one in every five (22%) U.S.
high school students reporting marijuana use at least once over the past month. Weed is also much more potent now than in decades past, with THC levels rising from 4% in 1995 to 14% by 2019. "Chronic use among adolescents has been linked to long-term changes in brain architecture," the study authors say, "resulting in impaired information processing and decreased cognitive, memory and attentive capacity in adulthood.
" So what effect might these impairments have on academics? To find out, Wang's team collected data from dozens of studies looking at marijuana use and academics and employment among youth. Some of the data was more reliable than others, but the researchers found "moderate-certainty" evidence that cannabis use in adolescence and young adulthood was linked to.
