Cannabis potency may influence severity of dependence

High-potency cannabis was associated with increased severity of dependence, particularly among young adults, while low-potency cannabis was not, according to data presented at the International Early Psychosis Association meeting.

“It is estimated that 3.8% of the world’s population used cannabis in the last year and this figure has remained relatively stable in the last decade. In England and Wales, however, prevalence of last year use dropped from 10.7% to 6.6% between 2002 to 2003 and 2013 to 2014,” Tom Freeman, PhD, of University College London, and Adam R. Winstock, MBBS, BSc, MSc, MRCP, MRCPsych, FAChAM, MD, of King’s College London, wrote. “Despite this overall reduction in use, demand for cannabis in addiction treatment services has continued to rise across the same time period. One possible explanation for these trends is an increase in cannabis potency. Data from cannabis seizures have documented rising [delta-9-tetrahydrocannabinol (THC)] concentrations in the U.K. This is predominantly due to an increase in the availability of high-potency, indoor-grown (skunk) cannabis.”

To explore this phenomenon, researchers surveyed 2,514 adults living in the U.K. about their drug use, including cannabis with high potency (skunk) and low potency (other grass, resin).

Frequent use of high-potency cannabis predicted greater severity of dependence (P < .001). This association became stronger as age decreased (P = .004).

Conversely, low-potency cannabis was not associated with dependence.

Frequency of all types of cannabis use was not a predictor of severity of cannabis-related concerns, according to researchers.

High-potency cannabis was significantly distinguishable from low-potency cannabis due to its effects on memory and paranoia. Further, high-potency cannabis reportedly produced the best high and was the most preferable and most available cannabis type.

“The illicit cannabis market is dominated by high-potency cannabis containing high THC and no [cannabidiol]. Our findings suggest that people who prefer this type cannabis are around twice as likely to show problematic use,” Freeman said in a press release. “The best way for people to reduce risk is to quit or cut down their use. If this is not possible, they should be encouraged to switch to low-potency cannabis.” – by Amanda Oldt

Reference:

Freeman T. Comparing different types of cannabis on cognition, reward and addiction. Presented at: International Early Psychosis Association Annual Meeting; Oct. 20-22, 2016; Milan.

Freeman TP, Winstock AR. Psychol Med. 2015;doi:10.1017/S0033291715001178.

Disclosure: Winstock is director and founder of Global Drugs Survey Ltd.