Researchers at the University of California San Diego have found that teenagers who start using cannabis may develop memory and thinking abilities more slowly than teens who do not use it. The findings were published in Neuropsychopharmacology and were based on data from more than 11,000 participants in the Adolescent Brain Cognitive Development (ABCD) Study, the largest long-term investigation of brain development among young people in the United States.
"Adolescence is a critical time for brain development, and what we're seeing is that teens who start using cannabis aren't improving at the same rate as their peers," said Natasha Wade, PhD, assistant professor in the Department of Psychiatry at UC San Diego School of Medicine and lead author of the study. "These differences may seem small at first, but they can add up in ways that affect learning, memory and everyday functioning."
Tracking Cannabis Use and Cognitive Growth
The research team followed 11,036 children from ages 9 to 10 through ages 16 and 17. During that period, the scientists monitored changes in cognitive performance as well as the participants' use of cannabis and other substances.
To measure cannabis exposure more accurately, the researchers used both participant reports and biological tests. Hair, urine and saliva samples helped identify drug exposure ranging from recent use to use that had occurred several months earlier.
