A new study out of Australia – eight years in the making – followed nearly 2,000 young adults in a public health project that found cannabis use has little effect on long-term memory and learning abilities.

Participants in the study were aged 20 to 24 when it began 8 years ago, and they were subjected to memory and intelligence testing three times over the course of the study. The participants were divided into three groups: heavy users, light users, and non-users/former users. Heavy users comprised 9% of the study group, while 18% were light users and the rest were non-users or former users who hadn’t ingested cannabis in at least a year.

The initial results of the study seemed to show that recent cannabis users did much worse on the tests than non-users, but when the results were broken down, the differences disappeared.

The lower education levels of the pot smokers — and their greater likelihood of being male — had made it look like marijuana had significantly affected their intelligence.  In fact, men simply tend to do worse than women on tests of verbal intelligence, while women generally underperform on math tests. The relative weighting of the tests made the impact of pot  look worse than it was.

The simple fact is that while cannabis has a psychoactive ingredient – THC – and if you’re really high you may talk slower and forget things, no one has proven that marijuana does any long term damage – or any damage at all for that matter – when it comes to cognitive abilities.

While opponents of marijuana legalization would like you to think marijuana is harmful, evidence mounts further everyday that it is not.

Joe Klare

5 Responses

  1. CannaCenters Medical Marijuana Clinics

    A new study from the National Institute of Mental Health (NIMH) explains the mechanism of action for tolerance and dependence with marijuana use. In order to understand this, you must first understand that the medicines in marijuana, called cannabinoids, attach to the body’s cells through a receptor, similar to how a key fits to a lock. Once the cannabinoid binds to the receptor, a chemical reaction takes place, triggering a message that tells the body to react in a certain way. Humans have two types of cannabinoid receptors, called CB1 and CB2.


  2. esoteric knowledge

    2/3 rds of the people didn’t smoke
    thats lame

    should be 50 or 70 percent smokers in the study oh well

    does that make me smarter than the non smoking scientists

  3. Bob

    They should have included me in this research study.
    I have Dyscalculia, AKA. Numeric Dyslexia.
    After a smoke my ability to recognize and process numbers actually improves.

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