File - In this May 5, 2011, shows a unidentified man smoking medical marijuana during karaoke night at the Cannabis Cafe, in Portland, Ore. (AP Photo/Rick Bowmer, File)
A new study links marijuana use at a young age to a decline in intelligence in adulthood, an irreversible decline.
Basically: pot smoking as teenagers can literally make you dumb.
That's how the lead scientist from Duke University characterized the conclusion of the research.
Researchers measured the I-Qs of 13-year-olds before marijuana use.
Then... measured their I-Qs again at 38-years-old, after years of pot smoking.
They found an average of an eight-point decline in intelligence levels.
The study also found people who started smoking pot as adults did not suffer any decline in intelligence.
Researchers think they know why prolonged pot smoking impacts the brains of teens and not adults.
Teenagers brains are not fully developed and are more susceptible to the adverse impacts of marijuana.