It’s easy to picture a daily marijuana user as forgetful and easily distracted, but is this a sign of the long term effects of weed on the brain? A 2001 study says no and makes the claim that any cognitive function discrepancies between lifetime user and non-user are virtually undetectable. This finding should certainly paint marijuana in a different light for those who fear brain deterioration and memory loss associated with heavy marijuana use.
The Study Methods
This study was published in the Archives of General Psychiatry and led by Harrison Pope, MD, of Harvard Medical School. The goal of this research was to determine the long-term effects that marijuana had upon brain function.
To do this, they gathered adults aging 30-55 years old and divided them into three separate groups: heavy users who used over 5,000 times in their lifetime and continued with to use daily, moderate users who had hit the 5,000 mark but used less than 12 times in the past 3 months, and lastly the control group of those who hadn’t used over 50 times in their entire lifetimes.
The investigation was set up to test cognitive functions such as word recall and ability to pay attention in each of the users at 0, 1, 7, and 28 days of not using marijuana. The purpose of this was to establish if the effects of weed on cognitive ability lingered after THC had been completely flushed out of the system, which can take anywhere from a few days to a couple weeks.
As THC Leaves, So Does Malfunction
Researchers discovered that the residual lingering effects of THC played a role in deterring cognitive functionality. At 0 and 1 day tests, performance from control subjects who had used very little versus heavy users was noticeably different. At day 7, the difference in capabilities was less apparent. Lastly, at day 28 the tests showed “virtually no significant differences” between heavy users and the control group.
These results have a big implication, which is that marijuana displays no apparent irreversible effects on the ability for the brain to function. While THC is still within the body, it certainly has influence over brain capabilities, but as it is expelled from the body, these negative effects of weed disappear.
Marijuana Affects Brain Function But Not Permanently
It is important to keep in mind that this analysis showed that cognitive function was still diminished in heavy users even while they weren’t actively under the influence of marijuana. However, this study affirms there is little risk in using every day for causing permanent damage to brain capacity.