Study adds to evidence that high strength cannabis is associated with an increased risk of becoming dependent

cannabis
Cannabis indica. Credit: Wikipedia

New data presented at this year's International Early Psychosis Association (IEPA) meeting in Milan, Italy (20-22 October) adds to accumulating evidence that high-potency cannabis in associated with an increased risk of users becoming dependent on cannabis. The analysis is by Dr Tom Freeman at University College London, UK.

Estimates suggest around 182 million people worldwide use cannabis each year, a number that could rise as legalisation of recreational use and/or medical use increases. Roughly 9% of people who try cannabis will become dependent on it at some point in their lifetime. People who are dependent on cannabis are often unable to cut down or quit, despite experiencing persistent negative effects from the drug.

Some people are more vulnerable to the harmful effects of cannabis than others. A number of factors may increase the risks of becoming dependent, such as being younger, male, and mixing tobacco with cannabis. Another possible factor is cannabis potency. The cannabis plant produces over 100 unique chemicals, and the two most abundant of these (delta-9-tetrahydrocannabinol or 'THC', and cannabidiol or 'CBD') can cause opposite effects on the brain and behaviour. In the last decade, the illicit cannabis market has become dominated by high-potency cannabis, which contains high THC and no CBD. This may explain why the number of people receiving professional treatment for cannabis problems has continued to rise.

Dr Freeman presents new data from a sample of over 400 young cannabis users in the UK. The sample were aged 16-23 years and 70% were male. 43% of those who preferred high-potency cannabis were dependent compared to 22% of those who did not. High-potency cannabis was associated with a two-fold greater risk of dependence (odds ratio 2.2) after adjusting for several confounders including age, gender, cannabis and tobacco use, biological markers of cannabis exposure (THC metabolites in urine, and THC and CBD in hair), and THC and CBD content in cannabis.

Dr Freeman concludes: "The illicit cannabis market is dominated by high-potency cannabis containing high THC and no CBD. Our findings suggest that people who prefer this type cannabis are around twice as likely to show problematic use."

He adds: "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 ."


Explore further

Dose-dependent link between cannabis use, psychosis relapse

Provided by International Early Psychosis Association
Citation: Study adds to evidence that high strength cannabis is associated with an increased risk of becoming dependent (2016, October 22) retrieved 27 May 2019 from https://medicalxpress.com/news/2016-10-evidence-high-strength-cannabis.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
203 shares

Feedback to editors

User comments

Oct 22, 2016
Wow. Sounds a lot like alcohol.
...or prescription painkillers.

Oct 22, 2016
This is nonsense. - There is no such thing as "dependency" except for children dependent on their parents for food, clothing and shelter.

The term was perverted and appropriated by prohibitionists and "treatment" quacks when they couldn't get away with calling marijuana "addictive" anymore. - When you look at the "criteria" for this imaginary condition, it turns out it refers to the repetition of ANY enjoyable behavior - like playing golf, watching movies or eating pistachios.

The campaign of lies supporting the monstrously destructive, counter-productive, freedom-strangling FRAUD of marijuana prohibition continues....

Oct 22, 2016
Why don't we teach the young people about this.Wernicke's encephalopathy and WKS is most commonly seen in people who are alcoholic, and only 20% of cases are identified before death. This failure in diagnosis of WE and thus treatment of the disease leads to death in approximately 20% of cases, while 75% are left with permanent brain damage associated with WKS.[2] Of those affected, 25% require long-term institutionalization in order to receive effective care.Also referred to as "Wet Brain" .

Oct 23, 2016
FDA's report to the DEA: Marijuana is no more addictive than tobacco, but doesn't seem to cause cancer. Dated August 2015.
DEA's reasoning for keeping marijuana a schedule 1 drug: Too many people tend to get it without a doctor's prescription.
This information was found in emails between department heads of the DEA and the FDA through the "freedom of information act".

Oct 23, 2016
more drug war BS.

Oct 23, 2016
The drug war Nazis strike again. If Marijuana were any great problem, it would have been a great problem a long time ago. When people drink beer, they drink more than they would when they drink hard alcohol. Stronger Marijuana makes one smoke less than one that smokes the weaker Marijuana. Duh!!!!!!!

Don't these propagandists ever get tired of spending our tax dollars on lies?

Oct 23, 2016
During my PhD I researched the cognitive psychopharmacology of addictive behaviour and psychotic symptoms. I am currently working as a research associate on a clinical trial evaluating a novel treatment for cannabis dependence. I am also working on a functional magnetic resonance imaging (fMRI) study, comparing the effects of different types of medical cannabis. I am interested in the use of experimental medicine to establish valid predictors of efficacy, in order to develop new clinical interventions.

Severe conflict of interest. He should be ashamed as a scholar.

Oct 23, 2016
Oh stop with the pathetic lies aleady and give it up No one believes this crap, I smoke high thc level medical and its no more addicting than drinking a glass of milk. Stop with the lies already , Its medically legal in half the country, No one is listening to this nonsense anymore. Ive smoked this off and on for over 40 YRS...40...That makes me the expert and authority on this subject, not some dumbass nerd in an office. And to have idiotic drs come on here and spout this crap is laughable lol.>SOrry Poirber do all the research you like, I an several other MILLION people that have used this for years know a hell of a lot better than you do. If you are predisposed to have an addictive PERSONALITY < then yes, those types of people will become Psychologically dependant on it, NOT PHYSICALLY. So stuff your weak lame ass novel treatment for the NON EXISTENT dependency on marijuana because it DOES NOT EXIST. What a pathetic way to get ahead in your profession. Lies lies lies.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more