Why the results of scientific studies on marijuana are at odds with popular experience

When it comes to cannabis and health, scientific research seems to be at odds with popular anecdotal accounts. Particularly, it is the case with studies which reported cannabis use causes harms to human health. For instance, some studies reported cannabis use causes mental illness but at the same time these studies acknowledge there may be others factors which are responsible for these health conditions. 

To address this conundrum it is important to address following questions. Why research on cannabis is not conclusive? Why it always end up with confusing results? Is it possible to carry out a study that can clearly delineate the  true underlying reasons of harms to human health? These questions need to be answered by the research community. Most often research on cannabis is not clear and conclusive making it very hard to draw a meaningful inference from the results of the study.

There can be two possible reasons for this ambiguity: firstly, it is not easy or possible to exclude other factors which may influence the relationship between marijuana use and other variables such as amount of drug used. Secondly, the research designs of the studies investigating marijuana use are made intentionally flawed to produce skewed results which may help to propel a particular view about the drug.

Referring to the challenge of clearly delineating the relationship between marijuana use and mental illness, National Institute for Drug Abuse (NIH) states, “several studies have linked marijuana use to increased risk for psychiatric disorders including psychosis (schizophrenia), depression, anxiety, and substance use disorders, but whether and to what extent it actually causes these conditions is not always easy to determine”.

NIH attributes this inability of scientific research to produce conclusive results to three factors – the amount of drug used, the age at first use, and genetic vulnerability. With a potential to influence the relationship between marijuana and mental illness, these variables   may distort the finding of any study that ignore their appropriate consideration.

It clearly calls for the research designs that allow distinguishing the variance caused by these factors from the variance actually caused by the variables under the investigation. This implies any future research on the link between marijuana and mental conditions, for instance, can only be credible and conclusive if it clearly figures out the variance caused by the variables of the study.

Turning to the second reason that causes studies to remain inconclusive may be related to vested interests to defame marijuana and strengthening the case of its prohibition. Many people points to big pharma who with their desire to keep marijuana suppressed, allocate hefty budgets to sponsor studies that produce skewed results. In this case, it is joint responsibility of every one of us to stop big pharma to deprive people from having an effective medication.

Though public support for marijuana is at all time high, yet a lot needs to be done to end the prohibition. Towards this end what we need most are unbiased scientific studies. More there is scientific evidence; less is the ambiguity about its harms and benefits and consequently, less is the opposition to marijuana’s decriminalization.