Teenage pot smoking tied to loss of IQ:

Teenage pot smoking tied to loss of IQ


Teens who smoke marijuana regularly may suffer long-term damage to their brains, new research suggests.

Age of onset for cannabis use and brain development seems to be key, said lead researcher Madeline Meier, a post-doctoral researcher at Duke University in Durham, N.C.

The researchers looked at how IQ scores changed between ages 13 and 38 in more than 1,000 participants from New Zealand who were born in in 1972 and 1973 and followed until age 38.

The key variable was the age of onset for marijuana use and the brain’s development, Meier said.

Before the age of 18, the brain is still being organized and is thought to be be more vulnerable to damage from drugs.

Persistent cannabis use appeared to affect everyday cognitive functioning, with persistent users showing more attention and memory problems than other participants, the researchers reported in Monday’s online issue of the PNAS.