As demand for research increases, we’re seeing a surge in the number of studies on cannabis and its effects. But much of it is sponsored by cannabis companies, potentially creating conflicts of interest for researchers and undermining the validity of their findings.
Numerous universities have recently received multi-million-dollar donations from the cannabis industry, raising questions around what companies expect in return for their support.
Why Cannabis Companies Sponsor Research
Many of these companies sponsor research because they want to use the results for marketing purposes, naturally creating vested interests that undermine the scientific process.
A common practice is to establish a weak argument as a null hypothesis and debunk it to make the sponsor’s products look superior. For example, researchers assessing CBD nano water might want to prove that CBD is more bioavailable when consumed via a specific product. A simple way to do this is to give test subjects both the product and CBD in its raw form and examine their blood serum levels of CBD an hour after consuming each.
Results may then show that CBD is more bioavailable when consumed via the product and will be cited as proof of its effectiveness. But this ignores the fact that few people take CBD in its raw form, or that numerous other consumption methods may make CBD more bioavailable than the water that’s being tested.
Another technique, known as P-hacking, centers on conducting a study multiple times and cherry-picking the one(s) with results that match a desired outcome. For instance, a test could be undertaken 20 times and produce the “correct” outcome twice. With P-hacking, the researchers would use those two sets of results even though most of their findings go against the desired outcome.
Sadly, many credible universities accept funding from cannabis companies even if it means compromising the integrity of a study, creating a hospitable environment for these kinds of practices.
Why Cannabis Researchers Accept Funding From Companies
Most universities would prefer to receive grants rather than funding from commercial enterprises, but many of them don’t have this option available to them. Lots of the labs studying cannabis are relatively new, making it difficult for them to be selective regarding which sources of revenue they accept.
Government grants aren’t always available to support basic cannabinoid and terpene research — particularly into the effect-based outcomes of interest to the average medicinal and recreational consumers — leaving a funding gap that cannabis researchers need to fill themselves. However, it’s worth noting that not all cannabis researchers bend to the will of their financial backers. Some publish the results of their studies regardless of their outcomes. But many cannabis researchers are still malleable, as evidenced by the bias we see in some of the studies funded directly by cannabis companies.

How Bias Appears in Research
There are multiple ways to manipulate studies to produce a specific set of outcomes. In addition to P-hacking, researchers can use small sample sizes, presenting the results of experiments with egregiously few participants to make “scientific” claims about a product.
Alternatively, they can define a study’s parameters vaguely. For example, researchers might compare a product to “pure CBD” without providing sufficient information regarding how the CBD was prepared. Many factors, including the preparation and delivery method, have a significant impact on the effect that CBD produces. However, by pretending they don’t, cannabis researchers can administer CBD in a way that ensures its effects compare favorably to those of the product.
The importance of dose-dependent responses is also regularly overlooked. If a study links a specific outcome to the consumption of a product, it often states that a higher dose will produce a greater amount of that outcome (for instance, a prolonged or more intense effect). Yet, many experiments simply compare one specific dose to no dose at all. Tests like these have no scientific value, and the need for greater integrity in cannabis research, for the good of the industry as a whole, is clear.
How Cannabis Researchers Can Eliminate Bias
If allowed to continue unabated, the effects of biased research could undermine the perception of the entire cannabis industry. However, studies with vested interests are systemic in most scientific disciplines, and experts in the cannabis sector believe that high-quality research will soon supersede the bad.
A wave of good research and subsequent meta-analyses should then yield substantive results. But until that wave arrives, cannabis researchers need to be proactive in eliminating bias from their studies. This progress requires them to adopt four strategies that will guarantee the validity of their results.
1. Preregistration
One of the best ways to eliminate outcome-based motives is to preregister studies. This strategy requires cannabis researchers to outline their design and commit to publishing their results in a journal before conducting them, thus ensuring that the data speaks for itself.
2. Use a Double-Blind Placebo
This strategy is best practice across a range of research-based disciplines. A double-blind placebo requires samples to be sent to the clinical research office to ensure the tested substance(s) and the placebos are indiscernible. This practice prevents the cannabis researchers who are conducting the experiment and those taking part from knowing what each participant has consumed, making the observed outcomes more reliable.
3. Look for a Dose-Dependent Response
Testing for dose-dependent responses is integral to forming solid conclusions. Taking precautions against false discovery rates for both type-one and type-two errors, doing multiple comparisons corrections, and mapping accurate dose-dependent response curves should form the basis of in-depth statistical analyses.
4. Employ Rigorous Statistical Testing
If a hypothesis is examined by comparing multiple groups, it’s essential to undertake rigorous statistical testing. This practice requires forming a null hypothesis (stating that the study will produce no observable difference between the groups examined) with a view either rejecting or not rejecting it.
Statistical testing can then determine the probability of producing an observable difference between the groups whereby, if the probability is less than a pre-agreed figure, the null hypothesis is rejected. This strategy can also be used to conclude whether that difference is statistically significant or due to chance.
Increasing credibility and trust
Biased studies have the potential to damage the cannabis industry, but there are many methods that cannabis researchers can employ to increase the validity of their work. Trustworthy studies must replace poor research to provide consumers and manufacturers with reliable information and subsequently enhance the perception of cannabis-based products. The long-term health of the industry may depend on it.
