Study shows true reality of what smoking weed in adulthood does to your brain
A study has revealed the numerous effects that smoking cannabis can have on you once you're older.
While a 2024 study has pointed out how much of an impact the habit can have on your health in your later years if you start doing it as a teen, this one focuses on adults in their mid-life.
Experts have previously claimed that smoking at a young age can mean you're 'growing your brain in a cannabis soup', but this research sets out to see if it affects cognitive function at all after the age of 40.
Last year's study found that regular users of the Class B drug had a lower IQ by 1.3 points on average, a difference that isn't big enough to shout about, after studying samples from over 5,000 men in a 44-year period.
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According to the United Nations Office on Drugs and Crime, it's estimated that 178 million people around the world consume cannabis, while a study from 2013 claimed that 13.1 million people were dependant on the substance.
The use of the drug is expected to rise among older people, especially with the medicalisation of cannabis to help treat chronic pain and as an antiemetic in cancer treatment.
This study set a precedent in investigating the effects on older people after other research suggested verbal learning deficits in young adults.
The study method
Back in 2016, a cohort study involving 1,897 Australians first recruited between 40 and 46 years of age were followed up four years, and then eight years later, though only 87 percent of participants took part in all three rounds.
The scientists aimed to examine within and between-person associations between cannabis use and cognitive function.
They would examine data and determine whether age-related changes in cognitive performance were at all affected by the use of cannabis use.
A number of tests were carried out on participants, including the California Verbal Learning Test, involving reading lists of words and recalling them over a series of trials, a Symbol Digit Modality Test, involving pairing geometric figures with numbers using a reference key, as well as Digit Backwards, simple and choice reaction time tasks.
To test premorbid verbal ability, which is a person's cognitive skills before a health condition, a spot-the-word test was carried out, all in each wave.
Self-reported cannabis use in the previous year was also noted by researchers in each wave.
Conclusions
The study found that the individuals who had worse immediate recall and showed a tendency towards worse delayed recall were those who used cannabis.
Those who didn't use the drug returned better results, after researchers factored in 'correlates of cannabis use' and premorbid verbal ability.
It was noted that these effects were caused by between-person differences, though no significant within-person associations between cannabis use and recall were found.
Ultimately, there was no clear evidence of greater cognitive decline in cannabis users with age, aside from the poorer verbal recall, though it was noted that 'this was not related to their current level of cannabis use', with there being no clear link between the drug and an accelerated cognitive decline.
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Topics: Drugs, Health, Mental Health
Joshua Nair