NEW YORK—Teens who routinely smoke marijuana risk a long-term drop in their IQ, a new study suggests.The researchers didnt find the same IQ dip for people who became frequent users of pot after 18. Although experts said the new findings are not definitive, they do fit in with earlier signs that the drug is especially harmful to the developing brain.”Parents should understand that their adolescents are particularly vulnerable,” said lead researcher Madeline Meier of Duke University.

via Teen pot use linked to later declines in IQ – The Denver Post.