High potency cannabis tied to greater use and risk in US youth

A new study published today in the scientific journal Addiction has found that young adults in the US do not 'titrate' when using strong cannabis. In other words, they do not use less cannabis to compensate for the stronger potency. In fact, it's the opposite: young adults who report using strong cannabis also typically use it more frequently and in higher quantities than young adults who use weaker forms of the drug. 

This study surveyed over 400 young adults in California USA who had used cannabis in the past month. They were asked to describe the strength of their typical cannabis product using a THC potency scale of 0 (no THC) to 5 (very high THC concentration). THC, or delta-9 tetrahydrocannabinol, is the main psychoactive compound in cannabis that causes those who use it to experience a 'high'. Nearly half of those 400 participants (195) said they routinely used high or very high potency cannabis flower. 

Participants disclosed how frequently they had consumed cannabis flower in the past month, how often they typically consumed in a single day, and how much cannabis they usually consumed per day. The participants who typically used stronger potency cannabis smoked cannabis more frequently and in higher quantities than participants who typically used low- or moderate-strength cannabis. Each step on the THC potency scale was associated with 3.33 more days of cannabis use per month and 0.13 more grams of cannabis flower used per day.

Each participant also answered a CUDIT-R questionnaire (Cannabis Use Disorder Identification Test – Revised), which identifies symptoms of cannabis use disorder. The participants' scores rose by an average of 1.21 with each level of THC potency, so that participants who reported typically using products with high or very high THC content had an average score of 11.2, compared with the average score of 7.0 for participants who usually used products with very low THC. A score of 8 or more on the CUDIT-R survey indicates potentially problematic cannabis use; a score of 13 or more indicates a possible cannabis use disorder. This cross-sectional study could not determine if using stronger THC increased risks of a cannabis use disorder or if those with a cannabis used disorder preferred using stronger cannabis.

In US markets, the average potency of cannabis flower has risen dramatically in the past few decades. Our study shows that young adults who seek out higher potency cannabis also typically use more cannabis and experience greater symptoms of cannabis use disorder. As the market for higher potency cannabis expands, we need to make sure young adults understand how important it is to know the strength of the cannabis they are using and the risks associated with cannabis use."

Dr. Michael Dunbar, Lead Author, RAND

This study was funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).