Marijuana permanently lowers IQ by several points in adolescents, according to research published in August. But a new study suggests that factors related to economic class and home life, not ...

A new analysis is challenging the idea that smoking marijuana during adolescence can lead to declines in intelligence. Instead, the new study says, pot smoking may be merely a symptom of something ...

IQ scores are on a decline, reversing a trend that saw scores rising at a steady rate during the 20th century, according to a new study. Researchers from the Ragnar Frisch Centre for Economic Research ...

Communities started adding fluoride to the water supply in 1945. But now, a new analysis finding a potential link between added fluoride and lower IQs in children is causing concern. The National ...

Environmental factors such as health and education played a role in both the rise in IQ scores during the 20th century, as well as a long-term decline dating back to the mid-'70s, a study from ...

The study found that people born in the 1960s and 1970s, when lead gas consumption was booming, may have lost up to seven IQ points at worst Stephanie Wenger is a TV Writer/Reporter at PEOPLE. She ...

Using marijuana at an early age could have long-term consequences on your brain and it may even lower your IQ, according to a new study in the Proceedings of the National Academy of Sciences.

NEW YORK (AP) — A new analysis is challenging the idea that smoking marijuana during adolescence can lead to declines in intelligence. Instead, the new study says, pot smoking may be merely a symptom ...