Today’s supercharged weed has experts concerned about misuse.
Thanks to the ingenuity of growers, cannabis is a lot stronger than it used to be, a pattern that started well before the recent wave of recreational marijuana legalization in the United States.
A new study raises concerns that this rise in high-potency cannabis strains may also be increasing the risk that new users will develop cannabis use disorder.
Symptoms of cannabis use disorder — also known as marijuana use disorder — include cravings, withdrawal, lack of control, and negative effects on a person’s life.
According to the authors of the study, published Dec. 17 in the journal Drug and Alcohol Dependence, the average tetrahydrocannabinol (THC) level of cannabis in the United States increased from 3.5 percent in 1994 to 12.3 percent in 2012.
The researchers also found that young people who started using cannabis when the average national potency was higher were more likely to go on to develop one or more symptoms of cannabis use disorder within a year of use.
The average national potency wasn’t linked to regular cannabis use or transition to daily use.
The study included 11- to 26-year-olds in Michigan with a high risk for substance use disorder. The authors caution the results may not apply to other groups.
Research estimates
Beatriz Carlini, PhD, MPH, a senior research scientist at the University of Washington’s Alcohol & Drug Abuse Institute, says whether there’s a link between cannabis potency and development of cannabis use disorder is an important line of research, but she doesn’t think the study answered that question.
She points to some of the study’s limitations. One is the use of average national cannabis potency, which is based on cannabis seized by U.S. drug enforcement agents over the years.
“It’s an OK measure of the increase in cannabis potency, but using it to study what individuals are doing in a local area is methodologically weak,” Carlini said.
Study author Brooke Arterberry, PhD, an assistant professor in the department of psychology at Iowa State University, says future research might focus on the potency of cannabis used by individuals.
“This would provide a better understanding of how potency and symptoms of cannabis use disorder might be related,” Arterberry said.
Carlini is also concerned about the study not finding a link between cannabis potency and regular use.
“If people aren’t using cannabis more regularly or daily — which is an important indicator and risk factor for developing a problem with cannabis — I’d stop the analysis there,” Carlini said.
Other research has looked at the link between cannabis potency and cannabis use disorder. Some of these focus on high-potency butane hash oil (BHO), also known as dabs or dabbing.
“There are studies showing that people who dab have more symptoms of cannabis use disorder, but they use cannabis more frequently and have more psychotic symptoms,” Carlini said.
One recent study found a link between BHO and higher levels of physical dependence, impaired control, and problems in school or on the job.
People often titrate — or use less of — stronger marijuana products to get the dose they want. This is similar to the way people drink beer in pint glasses but liquor in shot glasses.
Ryan Vandrey, PhD, an associate professor of psychiatry and behavioral sciences at Johns Hopkins Medicine, says potent cannabis products can be difficult to titrate, which may cause more problems.
“This could translate to greater [tolerance] to the drug, and then an increase in use, withdrawal, and other problems associated with it,” he said. “But that’s not the whole story. There are going to be other factors that come into play.”
One study found that living alone, using cannabis to cope, and recent life stressors were all linked to cannabis use disorder.
Vandrey says another problem is that the potency of marijuana products varies, and some people may switch to stronger products for the same or a bigger high.
“The high-potency products are geared and marketed towards the heavy daily user, which is the type of person that has cannabis use problems,” Vandrey said.
Although the link between potency and cannabis use disorder is still being investigated, Carlini believes enough is known about marijuana’s immediate effects to warrant regulating the potency of cannabis.
“I think it’s time, not because of cannabis use disorder, but because of data showing high levels of intoxication, paranoia, and psychotic episodes resulting from using high-potency cannabis,” Carlini said.
