Early Marijuana Use Linked to Lower I.Q.

A new study from Duke University suggests that teens who use Marijuana have a significant drop in I.Q. when measured later in life. "Parents should understand that their adolescents are particularly vulnerable,'" said lead researcher Madeline Meier of Duke University. Study participants from New Zealand were tested for IQ at age 13, likely before any significant marijuana use, and again at age 38. The mental decline between those two ages was seen only in those who started regularly smoking pot before age 18. To watch the KSL Video report on this story click here.