After nearly six years of comparing study results, researchers at Columbia University, the New York State Psychiatric Institute, and Swinburne University have found that prenatal cannabis exposure does not lead to cognitive impairment in children, based on data from decades’ worth of studies on this issue. The conducted an in depth review of all the research that’s been published to date, and again, found that there’s absolutely no evidence to support this belief about cannabis.

Another recently published study titled “Investigating the causal effect of cannabis use on cognitive function with a quasi-experimental co-twin design as found that there is “little evidence for causal effect of cannabis on cognition.” It showed clear evidence that cannabis use “does not cause a decline in cognitive ability among a normative cannabis using sample.”

It’s important to mention that studies can’t show whether cannabis actually caused changes in IQ. Instead, because there are so many other factors present in our environment that could be the cause of lowering IQ, even among individuals who use cannabis regularly, some of whom might have a lower IQ due to other factors. This is important to take into consideration if you ever come across a study suggesting that cannabis use lowers IQ. You can read more about this particular study here.

According to Forbes, the most recent study regarding prenatal cannabis study published this month in the journal Frontiers in Psychology review “revealed that a vast majority of studies on this topic found no significant statistical differences between kids who were reportedly exposed to cannabis during pregnancy, and those who were not. Less than 5% of comparable studies in this area showed any statistical difference between children’s scores on cognitive tests; importantly, these included both slight dips and improvements in scores, and all but 0.3% of study results still fell in the normal range.”