A recent article in the Proceedings of the National Academies of Science supports the notion that regular use of marijuana in one’s teen years has significant ramifications later in life.
Researchers concerned about the upswing in the use of marijuana in high schools wanted to emphasize the deleterious effects of cannabis on the developing brain of adolescents and the negative implications in later life. The study was aimed at encouraging increased efforts in schools to promote reduction of marijuana use among teens.
The Results of Adolescent Marijuana Use
The study showed that adults around 40 years of age who abused marijuana regularly in their youth performed poorly on cognitive tests as adults – losing IQ points and doing poorly on reasoning and memory tests when compared with similarly aged adults who used the drug much less frequently (or not at all). The study followed a little more than 1,000 people from New Zealand from the ages of 13 to about 38 years of age, conducting surveys and tests at the ages of 18, 21, 26 and 32 and then again right before turning 40.
Although individuals who continued to engage in smoking marijuana during their adult years showed lower IQ scores and a decline in cognitive skills, it was the ones who began smoking pot before they turned 18 that had the biggest decline in mental capabilities. Individuals who did not engage in pot smoking tended to gain slightly in IQ tests as they got older.
Individuals who did not engage in pot smoking tended to gain slightly in IQ tests as they got older
It was noted in the study that people who knew the pot users well noticed declines in memory and attention of the users in the prior year. This was the first test to implicate the use of marijuana and the decline of cognitive abilities over time. Other studies had shown a relationship between lower IQ and marijuana usage, but hadn’t ascertained whether this was the result of drug usage, or users having lower IQ’s at the onset.
Although New Zealand has a higher incidence of heavy marijuana usage than the United States, studies have shown that the potency of the drug is similar in both countries. The implications are clear, early marijuana usage has long term negative mental effects that could impact one’s future opportunities.