Teenagers, who smoke marijuana on a regular basis risk a drop in their IQ over the long term, said a new study recently released. Researchers did not find IQ drops that were the same for those people who became frequent smokers of marijuana after reaching the age of 18. Although researchers said the most recent findings were not definitive, they fit with earlier signs that marijuana is harmful to a brain that is developing.
The study’s lead researcher from Duke University, Madeline Meier, said that parents needed to understand that adolescents are the ones that are particularly vulnerable.
Participants in the study were from New Zealand and had their IQ’s test when they were 13 years of age, which was likely prior to any marijuana usage. Their IQs were tested again 25 years later when they reached 38. The decline in IQ between the two ages was evident only in those people that regularly smoked marijuana prior to turning 18.
A co-author of the study, Richie Poulton a professor at New Zealand’s University of Otago, said the results of the research send a message to stay away from the drug until you reach adulthood if possible. For many it is an issue of legality, but for Poulton he said it was an issue of health.
Marijuana is the world’s most popular drug that is illegal with an estimated 120 million to 225 million users from between 15 and 64 years of age, according to date from the United Nations. In the U.S., 23% of students in high school said they had recently smoked the drug. That percentage, makes the drug more popular than cigarettes, said the federal government in June.