What You Missed In September 2026
Author: Romina Garcia de leon, PhD Candidate, University of Toronto (Blog Coordinator)
What You Missed | September 2026
Science moves fast, and discoveries often pass by before we’ve had a chance to unpack them. This series is your monthly catch up with a science‑savvy friend: it’s evidence-based, accessible, and a little curious. Each post highlights meaningful new women’s health or sex and gender research from around the globe and asks the question: what does this really tell us about how our minds, bodies, and societies work?
Topic: Adolescence, social stress, and sex differences
Title: Distinctive behavioral and neurochemical profile of social stress in male and female adolescent mice
Authors: Ezequiel Monferrer , Rebeca Vidal, Tomás Aledón-Catalá, Michele Malaguarnera , Esther O’Shea, José Miñarro, M Isabel Colado, Marta Rodríguez-Arias
Journal: Biology of Sex Differences
Where is this research coming from? Spain
Adolescence is a sensitive period – the brain is still developing and stress during this time is associated with an increased risk of mood disorders, such as depression and anxiety. Social stress, which is often prevalent during adolescence (through experience like bullying or social rejection), is also linked to increased risk of mood disorders. Research is still catching up to understand how females and males differ in response to social stress during the adolescent period and what neurochemical changes occur that contribute to either susceptibility or resilience to stress across the lifespan.The current authors were interested in the kynurenine pathway, tryptophan can be converted to serotonin or alternatively the kynurenine pathway. Presence of more kynurenine metabolites over serotonin has been noted as a signature of depression.
To examine these questions, the authors used male and female mice to model social stress during adolescence. Male mice, given their territorial nature, were paired to enable engagement in direct aggressive encounters (this is a model of social stress commonly used in males). For females, this was modified so that they were to observe male-male aggressive encounters. Following these stressors, mice were put through a social interaction test: if they were more social with sex-matched counterparts, they were considered “resilient”, whereas if they rejected socializing, they were seen as “susceptible”.
The results showed that both sexes had increased corticosterone (the main glucocorticoid in rodents, equivalent to cortisol in humans) which demonstrates a physiological response to the social stressors. All mice were tested in various behavioural tasks, to measure behaviours such as anxiety-like behaviours, and anhedonia (loss of pleasure). In adolescence, resilient mice showed increased anxiety, which is usually seen as a negative response to stress. However, in this case the adolescent mice with higher anxiety-like behaviours, were in the resilient group. Female mice (both susceptible and resilient) showed increased anhedonia (loss of pleasure) in behavioural tests, but the same was not seen in males. Interestingly, in adulthood only females continued to show increased anxiety (mainly in the resilient females). This suggests that although some of the adolescent stress effects were transient, some sex-specific effects remain into adulthood. As for the kynurenine pathway, resilient females showed higher kynurenine levels across various brain regions compared to males. Susceptible males showed elevated serotonin in certain regions. This may suggest that the kynurenine pathway may be an important system to further explore in relation to social stress and adolescent risk to mood disorders.
What does this mean?
The study emphasizes the ways in which adolescent social stress affects males and females differently and that the kynurenine pathway may play a role in some degree of resilience to stress later in life. These studies help us get closer to identifying and potentially targeting certain systems to increase resilience in the face of stress. Preclinical work allows the research community to delve deeper into these neurochemical systems that may be driving the mechanisms underlying stress and mood disorder susceptibility.
Questions We’re Pondering
- Is there more research showing that higher kynurenine metabolites are a female-specific response to stress?
- Interestingly, the resilient mice had higher anxiety-like behaviours, could this mean that in some individuals, higher anxiety-traits may actually be a protective phenotype?
- Given the lasting anxiety-like behaviours in females, how can we be sure that the social interaction test was measuring resiliency in females?
Topic: Menopause, brain aging, and dementia
Title: Blood proteomics of menopause map to brain aging and dementia risk
Authors: Madeline Wood Alexander, Jennifer S. Rabin, Michelle Caunca, Allesandra Iadipaolo, Louisa Cornelis, Ria Warrier, Keenan A. Walker, Nina Miolane, Veronica Augustina Bot, Brendan Wood, Hamilton Se-Hwee Oh, Tony Wyss-Coray, Albert Pham, Julia Borger, Valentina Diaz, Emily W. Paolillo, Joel Kramer, Laura Pritschet, Caitlin Taylor, Matthew S. Panizzon, Ramiro Eduardo Rea Reyes, Marisa N. Denkinger, Nicholas J. Ashton, Sterling C. Johnson, Emily G. Jacobs, Rowan Saloner & Kaitlin B. Casaletto
Journal: Nature Medicine
Where is this research coming from? International – Canada, United States
Menopause – more specifically, certain biological changes related to menopause – has been linked to an increased risk of neurodegenerative diseases (such as dementia and Alzheimer’s disease). Thus, the menopausal transition may represent a critical inflection point in brain aging that has yet to be researched. The current study set out to investigate the molecular shifts that occur during menopause, as they may provide insight into how these shifts are related to brain aging and brain health.
The current study used four independent cohorts that included women during mid-life (such as pre-, peri-, and postmenopausal stages) and collected blood serum to look at molecular markers associated with brain health, including proteins related to inflammation, metabolism, synaptic function and other Alzheimer’s related biological markers. They also examined separate cohorts with cognitive data from women aged 60-72.
The authors found 16 proteins related to menopause (some specific to different menopausal stages) involved in inflammation, synaptic/neuronal signaling, metabolic pathways, and Alzheimer’s disease. The researchers created a “proteomic score” that included these protein levels. This proteomic score helped researchers track molecular shifts related to menopause. An important finding was that a higher proteomic score indicated increased molecular shifts and this was seen in women that had higher vasomotor symptoms (such as hot flashes, and night sweats). This demonstrates that certain menopausal symptoms are more than just a response to changes in hormones and ovarian aging – they are tied to a myriad of changes throughout the body. Supporting these findings, they also found that the older cohorts of women who had elevations in this proteomic score into their 60’s and 70’s were more likely to show signs of advanced cognitive aging and dementia risk. Another important element to highlight about this study is that these proteomic changes were seen not only in the brain, but across multiple organs, demonstrating that menopause is marked by multi-organ shifts.
What does this mean?
The findings of this study are changing the way we think about menopause. Midlife ovarian aging is not limited to the ovaries, or even one or two organs – it is a full-body cellular transition that involves multiple systems. Proteomic score changes during menopause were linked to Alzheimer’s disease years later. Future research and clinics could assess this score as a potential indicator of increased risk to later-life brain and cognitive outcomes.
Questions We’re Pondering
- How would taking menopausal hormone therapy influence this link between the increased proteomic score and dementia later in life? Would menopausal hormone therapy interact with these proteins and reduce the proteomic score during menopause?
- Are any of the shifts in protein levels related to genetic predispositions for dementia?
- What are ways in which we could mitigate the potential risk of dementia if this was a routine test for women during menopause?
Topic: Cannabis use, sex differences
Authors: Tracey Mackle, Lucia Colodro-Conde, Therese de Dassel, Tessa R Clarkson, Katrina L Grasby, Anastasia N Braun, Kylie Burke and Sarah E Medland
Journal: Addiction
Where is this research coming from? Canada
Cannabis research has become increasingly needed given the legalization of cannabis in 2018. There are many unknowns regarding the effects of cannabis, and which groups are using it more frequently. This information helps researchers understand which populations to focus on, and certain use trends could tell us about societal perceptions and influences of cannabis. Previous research has shown male dominance in use of cannabis. Delving into how cannabis use differs by sex (and whether/how this is changing over time) is an important piece to the puzzle.
The researchers of this study used an Ontario based health survey (which received answers from students in grades 7-12) from 1999 to 2023. Their aim was to examine male-to-female ratios for different cannabis-related outcomes to track population-level sex ratio trends over time. The authors looked at use patterns, perceptions, and risky behaviours.
The main findings of the study was that there is a change in the historically higher male-usage of cannabis. Where, they found a significant decrease in cannabis use over time for male students. Interestingly, as of 2023, cannabis use switched to being higher in females. The specific forms of use also revealed a sex difference, with higher daily use and past-12 month use in female youth. Females perceived cannabis as easier to obtain than males, which mirrored the use trends. As for risky behaviours, the male-to-female ratio remained consistent with higher dependence symptoms (in the past 3 months), as well as driving after cannabis use (in the past 12 months) in male youth.
What does this mean?
This research outlines an important shift in trends that is important for both cannabis researchers and policy makers. Given that interventions related to cannabis have historically been designed for and targeted at male populations, these findings highlight that female usage is also prevalent and should be taken into account in healthcare and educational settings. However, this research also demonstrates that risky behaviours related to cannabis use continue to be high in males, suggesting that targeted strategies should be developed to address this. In general, this research is important as it allows us to understand how trends are changing, which can inform future research questions and development of effective interventions.
Questions We’re Pondering
- Are there gender-related differences to cannabis use?
- What are some reasons or factors that have contributed to increased use of cannabis (and perceived ease in obtaining cannabis) in female adolescents? Are there any links to increased cannabis use and mood disorders? Could cannabis use aid, or be harmful to those experiencing depression and anxiety?
- How do cannabis use trends change in later life, past adolescence, and what are the implications?
