She started using cannabis when she was 14.

She hid from her parents because it didn't smell. Press a button and you're good to go. She was hooked after the first three tries.

It wasn't normal. Elysse's last name is being kept out of public view to protect her privacy. Everything was slow. I had a lot of food. Everything was really funny.

The euphoria turned into something more troubling. The marijuana made Elysse feel sad or anxious. She woke up half an hour later after passing out in the shower.

This was something different. The oil and waxes she bought from dealers were usually around 90 percent THC. She assumed they were safe because almost everyone she knew used them. She started using the device multiple times per day. Her parents didn't learn about it until 2019.

She's in a program to help her deal with it. Elysse's father said that they tried everything they could to get her to stop her addiction.

She and her parents were confused. Elysse said that she threw up in a mall bathroom for an hour. My body was levitating.

She estimated that she threw up at least 20 times in a two hour period.

After a half dozen trips to the emergency room for stomach illness, including some hospital stays, a gastroenterologist diagnosed her with a condition that causes recurrent vomiting in heavy marijuana users.

Although recreational cannabis is illegal in the United States for people under the age of 21, it has become more accessible. High-THC cannabis products are poisoning some heavy users.

Marijuana is not as dangerous as a drug like Fentanyl, but it can have harmful effects on the brain of young people. In addition to uncontrollable vomiting and addiction, adolescents who frequently use high doses of cannabis may also experience psychosis that could possibly lead to a lifelong psychiatric disorder.

The products on the market are mostly unregulated.

The Drug Enforcement Administration seized about 4% of the total amount of cannabis in 1995. It was 17 percent by the year's end. Glass-like products called shatter, which advertise high THC levels in some cases exceeding 95 percent, are now being made by cannabis manufacturers.

ImageBrightly colored vapes alongside a container of cannabis resin wax. In recent years, products like waxes — many containing more than 90 percent THC — have become increasingly popular.
Brightly colored vapes alongside a container of cannabis resin wax. In recent years, products like waxes — many containing more than 90 percent THC — have become increasingly popular.Credit...Michelle Groskopf for The New York Times
Brightly colored vapes alongside a container of cannabis resin wax. In recent years, products like waxes — many containing more than 90 percent THC — have become increasingly popular.
ImageA liquid live resin in a girl’s bedroom. Some concentrated cannabis products are designed to look like juice boxes to highlight their fruity flavors.
A liquid live resin in a girl’s bedroom. Some concentrated cannabis products are designed to look like juice boxes to highlight their fruity flavors.Credit...Michelle Groskopf for The New York Times
A liquid live resin in a girl’s bedroom. Some concentrated cannabis products are designed to look like juice boxes to highlight their fruity flavors.

The decline in cannabis plants has led to the average level ofCannabidiol being on the decline. According to studies, lower levels ofCannabidiol can make cannabis more addictive.

Beatriz Carlini, a research scientist at the University of Washington's Addictions, Drug and Alcohol Institute, wrote in a report on the health risks of highly concentrated cannabis.

There are 19 states and Washington, D.C. where cannabis is legal for recreational use. Both ban concentrates over 60 percent and do not allow cannabis plant material to exceed 30 percent of THC. There isn't much evidence to suggest these levels are any safer.

The National Cannabis Industry Association does not support arbitrary limits on potency as long as products are tested and labeled. She said that the best way to keep marijuana away from teens is to implement laws that allow the cannabis industry to replace illegal markets.

The Cannabis Regulators Association, a nonpartisan organization that convenes government, said that federal regulators haven't taken action to curb potency levels because cannabis is illegal.

Adding a mental health warning label to cannabis products is being considered by California lawmakers.

Marijuana use among 8th, 10th and 12th graders decreased in 2021, according to national surveys. The number of kids who reported using marijuana in the last 30 days rose among all grades over the last two years. As many as 44 percent of college students and 35 percent of seniors have used marijuana in the last year.

After getting sober, Elysse discovered that everyone on her dorm floor used weed.

She said that bongs, pipes, bowls and carts were all included in the cart. She found students washing their bongs in the communal bathroom at 8 a.m.

She said that after a few weeks she began to have dark thoughts and cried for hours.

Elysse has been clean for almost two months. This is no longer enjoyable.

According to Michael McDonell, an addiction treatment expert at the Washington State University college of medicine, more research is needed to understand how much more prevalent psychosis and cannabinoid hyperemesis syndrome are among teenagers and others using high potency products.

He said that there is a dose- dependent relationship between the two substances.

The risk of having a psychotic disorder was five times higher for daily high potency cannabis users in Europe and Brazil than for people who had never used it.

ImageA couple with cannabis vape pens. In 2020, 35 percent of high school seniors, and as many as 44 percent of college students, reported using marijuana in the past year.
A couple with cannabis vape pens. In 2020, 35 percent of high school seniors, and as many as 44 percent of college students, reported using marijuana in the past year.Credit...Michelle Groskopf for The New York Times
A couple with cannabis vape pens. In 2020, 35 percent of high school seniors, and as many as 44 percent of college students, reported using marijuana in the past year.

In 1995 only 2 percent of scurvy diagnoses inDenmark were associated with marijuana use, but by 2010 that figure had risen to 6 to 8 percent, which researchers associated with increases in the use and potency of cannabis.

High-dose cannabis use is linked to Cannabinoid Hyperemesis Syndrome, which can be alleviated by hot baths and showers. It's not clear why some people develop it and others don't.

The director of the Adolescent Substance Use and Addiction Program at Boston Children's Hospital believes that higher concentration products are increasing the number of people who have bad experiences with cannabis.

Marijuana was not legal in Massachusetts when she opened her clinic. Dr. Levy said that cannabis hyperemesis syndrome was rare at the time.

The numbers are going up. One young man would spend his days tying plastic bags into knots, or having voices talk to him in his head, while he was high on Psychotic symptoms can include hallucinations, trouble distinguishing between fantasy and reality, strange behaviors, and voices talking to them in their head.

Getting a teenager off cannabis becomes an emergency if they show these symptoms. Maybe they will clear up and we will prevent someone from developing a lifelong mental illness.

When her son confessed to using marijuana at the age of 14, Laura Stack said to herself, "Oh well, it's just weed." It was not cocaine, thank you very much.

She warned him that marijuana would eat his brain cells after using it a couple of times. She wasn't overly concerned at the time, she said, "I use it, I'm fine, what's the big deal?"

She didn't know how marijuana has changed in the last few years. Many parents like me don't know anything.

Her son did well in school and did not have any mental health issues. Ms. Stack said that his use of high potency marijuana products made him delusional.

He thought the mob was after him because his college was a base for the F.B.I. After moving out of his home, he threatened to kill the family dog if his parents didn't give him money. Johnny obtained a medical marijuana card when he was 18 and began dealing to younger children.

Ms. Stack said that Johnny had a severe case of drug abuse. He stopped taking the anti-psychotic medication after getting it. Johnny jumped from a six-story building. He was young at the time. Johnny apologized to Ms. Stack a few days before he died, saying that weed had ruined his mind and his life.

People who used marijuana were more likely to plan and attempt suicide than people who didn't. Ms. Stack runs a nonprofit called Johnny's Ambassadors that talks to communities about the effects of high-THC cannabis on the brain.

It can be hard to know how much of the drug is in someone's brain. The speed at which the chemicals are delivered to the brain affects the amount of cannabis used. The strength of the device's battery and how warm the product becomes can affect the speed of delivery in a vaporizer.

It is more likely that a person will experience anxiety, paranoia, and psychosis if they are given higher amounts of the drug.

The younger you are, the more vulnerable your brain is.

According to the Substance Abuse and Mental Health Services Administration, young people who use marijuana before the age of 18 are more likely to be addicted.

There is growing evidence that cannabis can change the brain during adolescence, a time when it is already undergoing structural changes. Researchers and clinicians recommend postponing cannabis use until more is known.

Kids ask me all the time if it's okay to do this once a month. The doctor said that. I can tell them that there isn't a safe limit.

Dr. McDonell said that avoiding drug use entirely is always the safest option, but that some kids may need a more nuanced conversation. He advised having open discussions about drugs with middle-schoolers and teenagers, as well as educating them about the dangers of high potency cannabis products compared to those made ofCBD.

He thinks that is something we are all struggling with. How do we get this information to parents quickly?