Marijuana is now legal for recreational use by adults in 10 states and the District of Columbia, and for medical use in 34 others. Its growing acceptance may lull both parents and teens into thinking it’s a relatively harmless substance.

However, today’s marijuana is far more potent than the pot of days past.

For one thing, the joints shared among the hippie generation had an average THC potency of two to three percent. Since then, marijuana has been selectively bred to produce products with as much THC as 20-30 percent.

Some products made from marijuana, often designed to be used with vaping devices—such as some edibles, oils, and substances called shatter, crumble, budder, and crystalline—have an even higher THC concentration, averaging 68 percent and occasionally as high as 95 percent.

Danger to younger users

Heavy use of high-potency marijuana during adolescence up to the age of about 30 has been associated with creating or worsening such mental health problems as anxiety, depression, psychosis, and suicidal ideation, as well as being 2.76 times more likely to initiate opioid use.

Other serious side effects have been reported in younger users, especially in Colorado and Washington, where recreational use was legalized first. Children’s Hospital Colorado in Denver reported 777 cases of cyclic vomiting, paranoia, psychosis, and other acute reactions among their emergency cases in 2015.

Bizarre side effect

The most recent unusual illness associated with habitual marijuana use in teens was reported last month in the journal JAMA Network Open.

People are showing up in emergency rooms complaining of severe abdominal pain and nausea, Dr. Sam Wang, a pediatric emergency medicine specialist, and toxicologist at Children’s Hospital in Colorado, told CNN recently.

“They vomit and then just continue to vomit whatever they have in their stomach, which can go on for hours,” he said.

Although not seen in every marijuana user, his analysis found over 800,000 cases of bizarre conditions in Colorado between 2013 and 2018. More than a third were in those under the age of 25.

Warn gently

Remember when you were a teen and your parents tried to warn you about various dangers? Then you’ll remember that lectures don’t work.

The best approach is to calmly encourage them to share their views with you, ask what they know about marijuana, and suggest they do their own research on the subject. Don’t try to frighten them, just enlighten them.

Then keep the lines of communication open. Encourage them to be honest with you, and provide guidance often.