Hartford — With surveys showing marijuana use among youth in Connecticut on the rise, substance abuse prevention groups gathered at the Legislative Office Building on Monday to launch a pre-emptive strike against any move to legalize marijuana for recreational use.

“We should not consider marijuana innocent until proven guilty given what we already know,” said Dr. Sandra Carbonari, a Waterbury pediatrician and immediate past president of the state’s chapter of the American Academy of Pediatrics. “Increased access for adults will increase access for youths, regardless of age restrictions.”

She cited research showing diminished memory, judgment and academic ability among youths who regularly use marijuana, along with a fivefold increase in the likelihood of using more dangerous drugs including heroin compared to their peers who don’t smoke pot.

Carbonari was among speakers at an event sponsored by the Connecticut Association of Prevention Professionals to call attention to the risks to the state’s youth they believe would ensue if the state were to follow in the footsteps of Colorado and legalize recreational marijuana. The group argues marijuana use is increasing among Connecticut youth since the state passed laws in 2011 decriminalizing possession of small amounts, and legalizing it for medical use for adults in 2012.

At the start of the legislative session, two “concept bills” were proposed to legalize recreational marijuana, but neither made it out of committee, said state Rep. Vincent Candelora, R-North Branford. Nevertheless, he said, there is pressure from some groups promoting it as an economic and tax revenue opportunity for the state that he expects will push to have a bill introduced in the 2017 session.

“With Connecticut’s tough economic challenges,” he said, “we don’t want to see the need for more revenue driving bad policy. We need to start educating our legislators now about the effects it’s having in Colorado.”

That state legalized marijuana for recreational use by adults just over two years ago.

John Daviau, executive director of the prevention professionals group, noted state Department of Public Health surveys showing that about 26 percent of teens reported using marijuana in the past month in 2013 compared to about 20 percent in 2009, a 20 percent increase.

“We can’t clearly link that to loosening of marijuana laws in Connecticut, but what else is there?” he asked. “Yes, I do believe they’re related.”

He also cited statistics showing that Colorado has gone from having the 14th highest rate of teen marijuana use 10 years ago to having the highest rate in 2015.

Carolyn Wilson, coordinator of the Groton Adolescent Substance Prevention Coalition, and Kerensa Mansfield, who leads a similar group in Ledyard, were among about 75 people at the event. Both are program coordinators at Ledge Light Health District.

“We want to make sure we stay on top of this issue,” Mansfield said.

Wilson said both groups want to “start the conversation” in the local community so that parents, youth and decision makers are educated about the health risks of marijuana use by youth and the problems that would be created by legalization for adults.

“Youth are so confused now about the laws about medical marijuana,” she said.

Mansfield and Wilson also said the Groton and Ledyard groups are interested in proposing their towns enact zoning laws that would prohibit cultivation facilities and dispensaries, as Guilford and Clinton have done.

“We want to be proactive,” Wilson said.

Also attending the event were about 20 students from Lyme-Old Lyme High School who are members of a group called “re@ch,” which stands for Responsible Educated Adolescents Can Help.

“It would hurt a lot of kids” if marijuana were legalized for recreational use, said David Brown, a senior at Lyme-Old Lyme High. After seeing family members struggle with addiction, he said, he has personal knowledge of the damage done by marijuana use.

“I don’t want to see anyone get addicted to marijuana,” he said. “It does destroy families.”

Other students in the group said they’ve seen the negative effects of marijuana use on their peers in school, and wouldn’t want it to become more easily available.

“I have a close friend who’s in rehabilitation from drug addiction, and marijuana is what got him started on other drugs,” said Liz Richard, a sophomore.

After the prevention group's event, the students met for about 45 minutes with state Rep. Devin Carney, R-Old Saybrook, and state Sen. Paul Formica, R-East Lyme. Four students shared personal stories about the effects of drug abuse in their families, said Karen Fischer, prevention coordinator at Community Action for Substance Free Youth, a program at the Lymes' Youth Service Bureau.

"It was very powerful," she said in an email message.

Three bills are under consideration pertaining to medical marijuana, Candelora said. Two pertain to expanding the legal use of medical marijuana for children, and the third deals with the palliative use of medical marijuana for hospice care patients, he said.

j.benson@theday.com

Twitter: @BensonJudy