AAN 2026: Sex and Gender Gaps in TBI Care, What Pharmacists and Clinicians Need to Know

In an interview with Pharmacy Times, Tatyana Mollayeva, MD, PhD, a scientist from the Rehabilitation Sciences Institute at the University of Toronto in Canada, discusses the critical gaps between traumatic brain injury (TBI) clinical guidelines and real-world practice with respect to sex and gender differences, highlighting her conversation at the 2026 American Academy of Neurology (AAN) Annual Meeting.

Mollayeva explains that although research on sex and gender in TBI has been evolving over the past 2 decades, the evidence base remains incomplete because clinical studies have historically excluded many populations, limiting the applicability of current guidelines. She calls for more inclusive research that intentionally targets historically underrepresented communities, and she anticipates that guidelines will eventually shift toward personalized medicine to ensure that care is truly responsive to the diverse needs of all patients.

Pharmacy Times: Can you introduce yourself and explain your current role?

Tatyana Mollayeva, MD, PhD: Hi. My name is Tatyana Mollayeva. I’m a scientist at the Toronto Rehabilitation Institute, University Health Network. This is a large hub of hospitals at the center of Toronto, Canada, and we are considered to be number 2 in the world in TBI care. I am also a professor at the Dalla Lana School of Public Health at the University of Toronto, with a cross-appointment at the Temerty Faculty of Medicine and the Toronto Rehabilitation Institute, University of Toronto. I also hold the role of Global Atlantic Fellow for Equity in Brain Health with the Global Brain Health Institute.

Pharmacy Times: Where are the most critical gaps between TBI guidelines and real-world practice when it comes to sex and gender differences?

Mollayeva: That’s a very important question, and I’m glad you asked, because I was trying to think about this myself as a person who has always sought evidence-based practice, which is often reflected in guidelines that direct clinicians on how to act in the best interests of their patients. The situation with sex and gender is an evolving field of research, so the evidence is still evolving. We started to talk about sex and gender not too long ago—probably around 2 decades ago in terms of conversation, but really only 1 decade ago when research started to pick up on these topics. It’s not that we didn’t want to do that; it was just not a focus, perhaps because our population was not aging so rapidly, or perhaps because we were more homogeneous in terms of our roles, responsibilities, and relationships in society, which are constructs that fall under gender.

Gender encompasses our roles, responsibilities, and relationships. A shift began to occur more than 2 decades ago, and more and more we have started to share roles that were traditionally assigned on the basis of biological sex. As this shift occurs, we begin to examine the evidence on it—and this remains an evolving field of study. It is a very important field of study that we must continue working on if we truly want to develop guidelines that will inform care responsive to people’s needs, because understanding this shift requires knowing what people do, how they do it, how they behave, and their relationships in society.

Regarding biological sex, it is also not a stable construct. Biology reflects our diversity in physiology, hormone levels, body structure, and organ function, and this diversity will continue. Without recognizing this, if we were to treat all people of similar sex the same, we would have a high probability of harming certain groups of people more than others. These are evolving topics involving evolving concepts—understanding diversity within the sex construct and within gender roles, responsibilities, and relationships.

To make this story relevant for policy and guidelines development, we need answers, and these answers are extremely difficult to obtain. If our studies are coming from samples that are not reflective of this diversity, then we are more likely to produce evidence that will not suit this diversity or be responsive to these diverse needs. This is problematic for many reasons, and it brings us to the topic of evidence—whose evidence we currently have that is informing clinical practice. We know that people have historically been excluded from research for many reasons, and there are communities about which we have no knowledge regarding any condition we care about.

In saying that, I do not want to sound pessimistic. I think raising this knowledge and talking about these topics brings us to a realization that there are uncertainties at many levels and that evidence is not expected to be discrete. But we have to be mindful of the individual patients for whom we care. These guidelines will probably one day move toward personalized medicine—this is when we will have to look at the person and understand their physiology, their hormone levels, their body structure and function, their elimination system, and how drugs are processed. Those will be very important sex considerations, because sex is a binary construct at only one point—but within one sex there is great heterogeneity, which often does not follow a Gaussian curve distribution. The distribution may be skewed in one group of people, or more normally distributed in another. Technically, looking at the mean as our answer may create—and more likely than not will create—harm to those who do not fit that mean.

I think we are doing well. Research is providing more and more evidence that these are important constructs that we have to care about. From a human perspective as well, clinicians recognize what they see in their offices—that people are different. Even people of the same age, similar race, similar occupation, and similar education respond differently to treatment and behave differently in terms of adherence to recommendations. Being mindful of this diversity is the first step. The next step is definitely to make research more accessible and to specifically target people who have historically been excluded from research, because we may learn something extremely important—something we have no idea about—which would direct us toward providing care that meets the needs of people, not just some people or some groups, but all.