More information is out on the impact of smoking marijuana as a teenager.  Marijuana proponents will tell you legalized pot is prohibited for sale to teens so the fact that there is more marijuana in the community universe it shouldn't affect teens.   Research shows that so far its true, teen use isn't up in most weed legal states and that's probably a good thing because the new studies indicate teen use can cause long-term damage to the brain.

Researchers from the University of Montreal tracked nearly 4,000 teenagers over four years and linked marijuana use with struggles tied to reasoning, memory, and inhibitions later in life.  Study participants had to rate how much they used marijuana each year on a scale from never (zero) to every day (five), as well as how many alcoholic drinks they consumed in typical day.

The scientists also looked at year-over-year changes in four cognitive areas: recall memory, working memory, perceptual reasoning, and inhibitions. They found teens who used marijuana every day performed the worst on cognitive tests more frequently, and that marijuana use in any given year was linked to impaired inhibitory control and working memory one year later.

Study authors say they were surprised that the effects of cannabis were more pronounced than the effects of alcohol and they were surprised of the lasting effects--for even if a young person reduced their use, you could still see effects from the previous year.