NEWPORT � Dr. Christian Thurstone said Colorado has seen health impacts of legalization of marijuana firsthand and most of it isn�t positive.



During a well-attended forum Monday night in the auditorium of the Newport campus of the Community College of Rhode Island, the child/adolescent and addiction psychiatrist said statistics show that 1 in 6 adolescents who smoke marijuana could become addicted and 13-year-olds who use the drug heavily could see an 8-point IQ drop by the time they are 38. Heavy users in the same age bracket are also twice as likely to risk psychosis in adulthood as their non-using peers, he said.



Thurstone continued that babies whose mother smoked marijuana while pregnant were much more likely to be depressed by the age of 10 and smoke marijuana themselves by the age of 14.



Reflecting on the current discussion in Rhode Island about potentially legalizing marijuana, Thurstone said it is important for people to look at the science before taking that step.



�There are people who need to be at the table, and needed to be there in Colorado,� Thurstone said. �Parents, priests, pastors, firefighters, police, teachers, they needed to be at the table, even now.�



Thurstone relied on a computer slideshow presentation, which used cited information to back up his comments. He took the crowd through what he said were the known health impacts of marijuana use, from before birth through adulthood.



Based on that information, the toll is especially heavy on younger children and adolescents, particularly because their brains aren�t close to being fully formed.



Thurstone said much of the marketing in Colorado for marijuana is aimed at capturing those groups. Pointing to edible marijuana products that resemble gummy bears and other popular candies, Thurstone said Rhode Island would have to be more active in restricting such products.



In Colorado alone, Thurstone said, there are now 827 retail marijuana stores, 1,145 marijuana cultivation facilities and 261 edible products on the market. And with that industry, Thurstone said, there have been a rash of problems as well.



He said there�s been a 40 percent spike in school-related drug issues since marijuana was commercialized in 2009. He also said the numbers show that 74 percent of the youngsters now in treatment for marijuana got access through someone with a medical marijuana card.



In addition to running an adolescent substance treatment program in Denver, Thurstone also works as an associate professor at the University of Colorado.



For his work to prevent adolescent substance use, Thurstone received a �White House in Action Award� in 2012 from the U.S. Office of National Drug Control Policy. He also serves as a member of the Science Advisory Board for the organization Smart Approaches to Marijuana.



Monday�s forum was sponsored by the Newport County Prevention Coalition and the Middletown Prevention Coalition.



The audience of about 100 people included a cross-section of the community, educators, doctors, municipal officials, police and former Rhode Island U.S. Attorney Peter Neronha and acting Rhode Island U.S. Attorney Stephen Dambruch.



After his presentation, Thurstone sat on a panel that included U.S. Attorney investigator David Neill, Ocean State Prevention Alliance Chairwoman Kathleen Sullivan and Kate Poniakowski, a young Rhode Islander who struggled with addiction.



In a wide-ranging question-and-answer session, the panel addressed a number of issues from why marijuana was gaining traction among youth to ways to stem that tide.



Poniakowski said she started smoking marijuana in the summer before she began high school, partially to escape problems at home, partially to fit in with her friends.



She said she progressed to harder drugs, including heroin, before eventually hitting rock bottom and seeking help. No matter what drug she was using, Poniakowski said, marijuana remained a constant.



�There�s not one addict that I know that did not start with marijuana, in my experience,� Poniakowski said.



Asked how to better reach youth before they make the wrong choice, Poniakowski said hearing from those who�ve gone down the wrong road seems to be the best way to accomplish that goal, but no one approach is foolproof.



�I know what didn�t work for me,� Poniakowski said. �You know, the health classes, they give you the posters and the pamphlets and then you do all this stuff and it�s all textbook. I didn�t care about what was in those pamphlets.�



�The more we educate kids, the more they�ll make the correct decisions,� Neill said.



�We need to do a lot more as communities, working together to change laws and policies,� Sullivan said. �Unfortunately, we�re moving in one direction with alcohol and tobacco, but this fast-moving train with marijuana is moving right in the other direction and I suspect it will be about 10 years before we see the full health effects of this.�



Rhode Island already has an active medical marijuana program, with more than 17,000 license-holders in the state.



Depending on who�s speaking, there may be significant support to make recreational marijuana use legal in the Ocean State, while others say such a move would open Pandora�s box. In recent weeks, people on both sides of the argument have actively made their cases, including state Attorney General Peter Kilmartin, who�s been an outspoken critic of legalization.



Possession of less than an ounce of marijuana has been decriminalized in Rhode Island, with such cases handled in the state Traffic Tribunal and typically netting fines.



Some legislators have recommended sending the matter for review by a state study commission, a move they�ve said would help avoid the pitfalls experienced in other communities; others have called that a stall tactic.



Sheley@NewportRI.com