According to new research, the effects of marijuana on young brains diminishes 72 hours after use.
The analysis, which was published in the journal JAMA Psychiatry on Wednesday, used a combination of data from 69 previous studies to look at the effects of heavy marijuana use on young people’s cognitive functioning.
People who had identified as heavy users saw significantly lower scores than non-users in a variety of cognitive domains. This included learning, speed of processing, delayed memory, and attention.
The lead author on the study, Cobb Scott, remarked, “There have been a couple of meta-analyses done in adult samples, but this is the first one to be done specifically in adolescent and young adult samples.”
“We looked at everything from learning and memory to different aspects of executive functioning such as abstraction ability,” Scott further said. “And we basically showed that the largest effects — which was around a third of a standard deviation — was in the learning of new information and some aspects of executive functioning, memory and speed of processing.”
When comparing marijuana users to non users on the length of abstinence from marijuana use, the difference in cognitive functioning was longer apparent after 72 hours of marijuana abstinence.
According to Scott, this means “that some of the effects found in previous studies may be due to the residual effects of cannabis or potentially from withdrawal effects in heavy cannabis users.”
