Sponsorship of Marijuana research may bias the results

Posted January 27, 2023 on Psychology Today

A new study explores the effect of corporate support for cannabis research.

An innovative new study challenges naïve acceptance of research funded by the cannabis industry. The study’s authors reviewed Canadian research articles available through PubMed that contained an acknowledgment of financial conflicts of interest and/or direct financial support by cannabis corporations.

The study found evidence of a “funding effect” on research integrity, research agendas, and the evidence base available for decision-making. This “finding effect” is like that documented with research funding by the pharmaceutical, tobacco, alcohol, and food industries.

A little context to this study is useful. In October 2018, Canada became the second country to legalize cannabis. Several cannabis corporations had already formed in anticipation of legalization, and just one month later, in November 2018, two Canadian universities announced cannabis company-sponsored research chairs.

Academic laboratories eager to undertake research required two things to get started: grant money and cannabis. The only source of research-quality cannabis was the emerging cannabis companies, and they were eager to fund research designed to their liking. There was nothing necessarily nefarious about financial relationships between researchers and corporations; it's just good business. And if you were an academic or graduate student needing to publish to advance your career, what would you do?

The two largest Canadian cannabis companies dominate the industry’s financial support for research. Their dominant funding presence likely reflects their dominance within its market in terms of revenue and market capitalization. As such, they represent the leading edge of Big Marijuana. As with other peer industries, their sponsorship of research is associated with research agendas, outcomes, and conclusions favourable to their company goals.

Of 72 articles with industry support and disclosed conflicts of interest, prevalent topics included cannabis as a treatment for a range of conditions; as a tool in harm reduction related to other substance use; product safety; and preclinical animal studies. There was a paucity of high-quality double-blind studies and research on potential harm done by industry marketing practices, including impacts on at-risk populations.

Scientists across multiple surveys reported the perception that industry funding is associated with shifts in research agendas toward more applied research with commercial applications. The resulting “funding effect” has been documented to be statistically and positively associated with research outcomes and conclusions favorable to the funders. As the new study reports, "Corporations also seek to shape evidence and policy environments through financial relationships with key opinion leaders–respected, credible, and influential experts within the cannabis field–that hold perspectives supporting company positions. By providing key opinion leaders with paid consultancies, advisory board memberships, and speaking engagements," Big Marijuana raises the profile of like-minded experts above scientists researching potential harms created by their products. Not all of these financial relationships are contained in PubMed’s conflict of interest statements, which means the current study probably underestimates the degree of “funding effect” that exists.

The study concluded:

Our findings suggest that Canadian cannabis companies, around the time of legalization of their product in Canada, conducted research activities akin to peer industries such as pharmaceuticals, tobacco, alcohol, and food in three ways: sponsoring research related to product development and testing, expanding indications of use, and financially supporting key opinion leaders.

These efforts may have biased the evidence base available for decision-making.

I trained in psychiatry at a time when major pharmaceutical companies began dominating research funding in many academic psychiatry departments. I watched as this distorted the training of psychiatrists, away from more humanistic approaches to psychotherapy and more exclusively toward reliance on pharmacotherapy. I even remember an article extolling psychotherapy as a means for getting patients to comply better with their prescription medication. The “funding effect” may look innocent on the surface, but its power can distort an entire field of inquiry.

It is important to end naiveté about corporate funding of research, even by industries one might have favorable feelings toward.