Teen Cannabis Use Contributes To Long-Term Memory Loss
Long-term marijuana use may impact memory, according to recent findings published in the journal Hippocampus.
Researchers at Northwestern University studied how teenage marijuana use was connected to poor long-term memory later in life.
"The memory processes that appear to be affected by cannabis are ones that we use every day to solve common problems and to sustain our relationships with friends and family," senior author Dr. John Csernansky from Northwestern University, said in a news release.
Researchers found that young adults who abused cannabis as teens performed about 18 percent worse on long-term memory tests when compared to adults who never used the drug. Furthermore, the longer they used it, the greater the differences were in the shape of their hippocampus.
Researchers believe that this abnormal shape may reflect damage to the hippocampus, including the structure's neurons, axons or supportive environments.
For the study, participants between the ages of 16-17 took a narrative memory test that involved listening to a series of stories that were about one minute long. They were then asked to recall how much content they could remember 20 to 30 minutes later.
Close to 100 participants were involved in the study, all of whom had not smoked marijuana for about two years prior to involvement. However, at the beginning of the study, researchers asked the teens to start using the drug daily for the next three years.
"It is possible that the abnormal brain structures reveal a pre-existing vulnerability to marijuana abuse," lead author Matthew Smith said. "But evidence that the longer the participants were abusing marijuana, the greater the differences in hippocampus shape suggests marijuana may be the cause."