Marijuana and Opioid Use Linked to Inability to Consider Future Behaviors

"Cannabis-related disruption of cognitive functioning extends to the capacity for episodic foresight."

by Josie Rhodes Cook

Bad news, stoners: A new study suggests that regular cannabis users may have difficulty with episodic foresight or the ability to consider future behaviors.

The findings, out of the Australian Catholic University, were published last month in the Journal of Psychopharmacology. Study author Kimberly Mercuri told PsyPost she has “always been interested in the psychology behind problem behaviours,” and when it comes to substance dependence, “many individuals were able to function relatively well on the day-to-day,” but her study found that when it comes to the future, cannabis users had difficulty even imagining possible scenarios.

“Cannabis use is associated with a range of neurocognitive deficits,” Mercuri’s study in the Journal of Psychopharmacology reports. “However, no study to date has assessed whether these difficulties extend to episodic foresight.” The findings of Mercuri’s study suggest that, in fact, they do.

Weed users may have difficulty with episodic foresight. 


Episodic foresight is “the ability to project oneself into the future and mentally simulate situations and outcomes,” according to Advances in Child Development and Behavior. To measure this, the participants in Mercuri’s study had to complete the Autobiographical Interview task, requiring them to respond to a cue word by describing an event that already occurred in the past or envisioning a future event, ZME Science reports.

According to the findings in the study, regular users of cannabis showed greater impairment of episodic foresight and episodic memory than either recreational users or the control participants who didn’t use cannabis.

The study assessed 57 regular cannabis users (23 recreational, 34 regular) and 57 control subjects. That seems like a rather small sample size, but Mercuri seems confident in her findings. She tells PsyPost:

The findings indicate that with regular cannabis use the ability to mentally time travel is negatively impacted; relative to people who have never used the drug and those who use it infrequently.

That weed could really mess with her foresight.

Comedy Central

Mercuri told PsyPost that regular cannabis use could impact things like decision-making and goal-setting.

And opiate users don’t get a pass on this one, either. “This deficit is not isolated to cannabis users, with another paper of ours indicating a significant impairment in future thinking observed in long-term opiate users,” Mercuri told the outlet.

Mercuri did admit that more research is necessary to better understand the findings and their implications. In the meantime, pot smokers may just have to contend with the possibility that their ability to think about the future may be impaired by their habit; but there’s always a chance that they’re totally cool with that outcome, anyway.

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