FRIDAY, May 29, 2020 (HealthDay News) -- Marijuana has long been linked to a host of mental health risks, but the potent strains sold today may amplify those dangers, new research suggests.
"We know that people who use cannabis are more likely to report mental health problems than those who don't use cannabis, but we don't fully understand how recent increases in the strength and potency of cannabis affects this," explained study author Lindsey Hines, a senior research associate from the University of Bristol Medical School in England.
For the study, researchers examined data from a large, ongoing British study and focused on more than 1,000 people who were born in the early 1990s and reported recent pot use when they were 24. The scientists were also able to track which participants had suffered mental health problems as adolescents.
Among those who said they had used pot in the previous year, 13% said they had used high-potency cannabis.
Those who used high-potency pot were four times more likely to have problems with marijuana and two times more likely to suffer from anxiety than those who consumed lower-potency weed, the researchers found.
"People who use cannabis are more likely to report mental health problems than those who don't use cannabis, but reducing the potency and regularity of their cannabis use may be effective for lessening likelihood of harms from use," Hines said in a university news release.
"In countries where cannabis is sold legally, limiting the availability of high-potency cannabis may reduce the number of individuals who develop cannabis use disorders, prevent cannabis use escalating to a regular behavior, and reduce impacts on mental health," she added.
The report was published online May 28 in the journal JAMA Psychiatry.
This is not the first time marijuana has been tied to mental health problems: Research published in April in the journal Advances in Preventative Medicine found nearly half of people who have been or are now dependent on pot have some form of mental illness or dependence on another drug. That compares with 8% of people with no history of pot dependence.
Study author Esme Fuller-Thomson told HealthDay at the time that the study doesn't answer which came first, nor does it prove heavy pot use causes mental problems, but it does show a strong link.
"Not everyone that uses pot is going to develop mental health problems," said Fuller-Thomson, director of the Institute for Life Course and Aging at the University of Toronto.
Fuller-Thomson said she was concerned that legalization of pot will worsen mental health problems, especially among teens and young adults. Most users start as teens, and marijuana can harm the developing brain.
"My kids have to walk by three shops selling marijuana on their way to high school," she said. "We're now doing this very dangerous experiment on adolescents and young adults."
One psychiatrist agreed the trend is troubling.
As legalization of recreational marijuana spreads across the United States, more people are showing up in ERs with psychotic symptoms after consuming too much pot, said Dr. Itai Danovitch, chairman of psychiatry and behavioral neurosciences at Cedars-Sinai in Los Angeles.
"If somebody gets too high, they use more than intended, they can have psychotic symptoms. That typically resolves as the drug wears off," Danovitch said.
But some unlucky souls with a family history of mental illness might wind up with a full-fledged psychotic disorder that requires extended treatment, he noted.
"That risk is concentrated among a minority of people who have an existing vulnerability to develop a psychotic disorder, a family history of psychosis," Danovitch explained. "There are environmental factors that influence whether somebody develops schizophrenia who has a risk. It appears cannabis probably is one of those factors."
For more on cannabis, head to the U.S. National Center for Complementary and Integrative Medicine.
SOURCES: University of Bristol, news release, May 28, 2020; Advances in Preventative Medicine, April 15, 2020