Cannabis Use Disorder Affects 22 million People Worldwide

October 31, 2023

Mohd Aasim

Cannabis Use Disorder (CUD) represents a growing global health concern, impacting an estimated 22 million individuals worldwide. The use of cannabis is on the rise and has led to an increasing number of individuals seeking treatment for CUD in nearly every region of the world. Despite the availability of psychosocial treatment options, their efficacy remains modest, and long-term outcomes are uncertain. Moreover, there is currently no approved pharmacotherapy for CUD, underscoring the urgent need for effective interventions.

Chronic cannabis use is associated with cognitive impairments, particularly in verbal learning and memory. While the evidence for the impact on other cognitive functions like response inhibition, working memory, and verbal fluency is mixed, it raises concerns about the potential long-term effects of cannabis use on cognitive abilities. Studies have also indicated that individuals seeking treatment for cannabis-related issues often exhibit impaired cognition.

This cognitive impairment may be linked to the lingering effects of cannabis exposure, but the evidence regarding the recovery of cognitive function during abstinence is inconclusive. To further investigate these issues, participants for a clinical trial were recruited through various means, including website advertisements, forums, and community flyers.

Inclusion criteria for participants were strict and included:

Age between 16 and 60.
A diagnosis of CUD of at least moderate severity
An expressed desire to quit cannabis use within the upcoming month.
A history of unsuccessful attempts to quit.

Co-administration of cannabis with tobacco and providing a positive urine sample for THC-COOH were also required for inclusion. Women of childbearing potential and men were required to use effective contraception during the trial.

Demographic details of the participants in each treatment group are outlined in Table 1. The sample of 70 participants primarily consisted of young adult males, with a mean age of 26.3 years. Notably, early in the trial, the criteria for participant age and vital signs were adjusted to enhance the generalizability of the findings.

Throughout the trial, participants adhered closely to their treatment plans, with only a few exceptions. The attendance rate at the end of treatment was exceptionally high, demonstrating the commitment of the participants. The study reported no significant difference in the number of mild and moderate adverse events between the placebo group and the groups receiving different doses of CBD (cannabidiol). Fortunately, no severe adverse events were recorded during the trial.

The study employed a comprehensive battery of cognitive tasks to evaluate performance before and after a four-week treatment period with daily oral doses of 400 mg CBD, 800 mg CBD, or a placebo. Surprisingly, the results did not align with the initial hypotheses. There was no evidence that CBD had an impact on delayed prose recall compared to the placebo. In fact, CBD showed minimal effects on most cognitive outcomes, except for a notable dose-by-time interaction.

The significant dose-by-time interaction indicated that the group receiving 800 mg of CBD experienced improved performance in backward digit span, a measure of working memory, from baseline to week four. However, on the primary outcome measure, delayed prose recall, all groups demonstrated improved performance from baseline to week four.

The study’s findings suggest that CBD may not exert broad cognitive effects on individuals with CUD. Nevertheless, there is evidence that CBD could have a beneficial impact on working memory manipulation. These results underscore the need for further research to better understand the potential benefits and limitations of CBD as a treatment for CUD and associated cognitive impairments.

Journal Reference

Lees R, Hines LA, et al. Effect of four-week cannabidiol treatment on cognitive function: secondary outcomes from a randomised clinical trial for the treatment of cannabis use disorder (Berl) 2023 Feb;240(2):337-346. doi: 10.1007/s00213-022-06303-5.