Melissa is a mother of 2, lives in Utah, and writes for a multitude of sites. She is currently the EIC of and writes about health, wellness, and business topics.

A new study on the effects of marijuana on the brain indicates that the effects of the drug disappear within 72 hours of use. The study focuses on cannabis legale and the impact it has on adolescents and young adults.

The study wanted to find the association between cognitive dysfunction in adolescents and young adults and heavy cannabis usage. Researchers did not study consumption devices, so there is no data to indicate if there are differences between cannabis usage when it is consumed using a vaporizer versus that consumed using a bong or water pipe.

The study analyzed 69 cross-sectional studies, with 2152 cannabis users finding that there was a significant reduction in cognition in those that reported frequent cannabis usage. Cannabis light usage was not included in the study. The study analyzed the impact among heavy users after abstinence from cannabis for 72 hours or longer.

Researchers concluded that the cognitive deficits were small or not significant.

The study concludes that long-term, heavy usage of cannabis may result in a small reduction of cognitive function. Abstinence from cannabis will diminish this cognitive decline.

Researchers note that the public view of cannabis is changing, and perceived harm from the drug is decreasing. A notable side effect of heavy usage is poor cognitive function, especially among youths. Meta-analysis has been previously done on adult samples, but this study is the first that focuses specifically on adolescent and young adult samples.

The researchers found that heavy usage leads to a significant decline in cognition, with as much as a third of a standard deviation difference. Learning new information was impacted as well as memory and processing speed.

The difference in cognition between heavy users and non-users was not apparent after 72 hours of last smoking marijuana. Scientists assert that previous studies that show cognition decline may be due to residual effects of cannabis. Withdrawal effects may also be possible for some of the participants and lead to cognitive decline, according to the study.

Inconsistent results have been previously recorded for the long-term cognitive effects of marijuana usage. A study conducted in 2008 found that early-onset usage and heavy usage of marijuana led to poorer cognitive performance for executive functioning tasks as well as episodic memory.

Studies from 2014 warn against heavy usage, or any usage of marijuana, while a child’s brain is still in development.

Researchers that conducted the new study claim that the study is bad for marijuana users and shows that there are worse cognition outcomes for users versus non-users. The 72-hour time frame was chosen because previous studies show withdrawal effects cease after 72 hours, so researchers wanted to examine data from after the peak of withdrawal symptoms.

CNN recently ran a report that shows opioid users are turning to medical marijuana, trading in their pills for the safer, easily acquirable marijuana. The finding is significant due to the rise in opioid deaths in the United States. Opioids killed more Americans than breast cancer in 2016, with overdoses becoming a key point in political campaigns.

Doctors suggest that cannabis must be used properly to help treat opioid addiction, but warn that cannabis is only one form of treatment and will not work for all drug users.