Jens C. Pruessner

Psychosocial stress engages coordinated physiological and neural responses that enable adaptation to environmental challenges. Maladaptive stress responses and reduced resilience are major risk factors for psychiatric and neurodegenerative disorders. As the brain’s metabolic response to stress remains largely unexplored, we used simultaneous [ ¹⁸ F]FDG PET/MRI during performance of the Montreal Imaging Stress Task to assess cerebral glucose metabolism, BOLD activation and functional connectivity. Multimodal data analysis identified the posterior cingulate cortex (PCC) as hub of stress processing beyond cognitive input, with increased glucose metabolism and attenuated BOLD deactivations. This was accompanied by reduced PCC connectivity within the default mode network and increased influence onto frontoparietal and dorsal attention networks. Endocrine stress responsivity was further reflected in lower resilience sub scores, failure to downregulate anterior cingulate cortex (ACC) metabolism during stress, and an inverse relationship between ACC glucose metabolism and anterior insula functional connectivity. These results indicate that acute psychosocial stress does not merely increase overall energy demand but reconfigures the relationship between regional metabolism and large-scale network organization, which further differs with individual endocrine stress responsivity. Our findings unify the roles of stress and the DMN in brain disorders, providing a multimodal framework for assessment in patient populations.

In psychoneuroendocrinology (PNE), data is valuable due to its high clinical and health-related relevance and resource-intensive data collection yet sharing it openly alongside publications remains uncommon. If shared, data remain highly fragmented and non-standardized, which hinders data reuse and integration across studies. To address this, we formed a consortium and, as a first step, conducted this study using a modified Delphi approach across two survey rounds to inform about important considerations regarding data structure, metadata, subject-level variables, and implementation requirements before a data standard for PNE may be developed. The panel in the final round consisted of 50 responders from the field of PNE. In two online survey rounds, respondents rated their agreement with 84 statements anonymously on a 5-point Likert scale. Consensus (> 70% [dis]agreement) was achieved for 80 items. The results highlight a broad agreement within the PNE community on the need for, and key components of, a standardized data structure, including a balance between flexibility and standardization to allow for adaptability across many use cases as well as comparability. Developing and establishing a standard for PNE data will be a central next step to foster transparency, sustainable use of resources, and the translational potential of our work.

Stress has been linked to the consumption of palatable food and may contribute to the development of obesity. Interindividual differences in cortisol stress reactivity are discussed as mediating mechanisms, yet findings linking food craving to cortisol reactivity are heterogeneous. Methodological differences in whether participants receive a sugary preload or are invited fasted may contribute to these divergences. Hence, this study set out to systematically investigate the effect of glucose and psychosocial stress on food craving in healthy adults. Overall, 62 healthy, fasted adults (mean age = 23.13; SD = 3.02; 54.84 % female, 45.16 % male) reported current food craving on the Food Craving Questionnaire, received either glucose or water and were later exposed to psychosocial stress or a friendly control condition. After stressor exposure, food craving was assessed a second time. We repeatedly assessed salivary cortisol and blood glucose and used linear mixed models to test whether the experimental manipulations predicted changes in craving and explored associations with sex and stress-eating tendency.Blood glucose increased in those consuming glucose and the stress test increased cortisol significantly. Higher cortisol reactivity, and even stronger, a greater increase in blood glucose led to significant reductions in food craving over time. We found no supportive evidence that glucose and cortisol reactivity interactively affected craving. These findings suggest that short-term metabolic signals may be more influential in shaping immediate food craving than acute stress, and that acute cortisol elevations may not universally promote food craving.

Objective: Cognitive rigidity is a transdiagnostic process observed across various psychopathologies and commonly targeted in psychotherapy. This study investigated whether a random input technique (RIT)-based inspiration tool enhances creative cognition in adults with psychiatric disorders. Method: A total of 100 adults with a lifetime psychiatric disorder were randomized to either an inspiration tool (Brain2Business™ small) combined with brainstorming rules (B2B + BS) or brainstorming rules alone (BS) in a participant-blinded randomized controlled trial. Both groups completed their respective condition during two face-to-face psychotherapeutic interventions, followed by home-based sessions over 5 days. General, subjective, and objective creative cognition—including fluency, flexibility, and originality—were assessed. Results: Compared with BS, the B2B + BS condition increased objective creative cognition (SMD = 0.37, p = .049), including fluency (SMD = 0.43, p = .024) and flexibility (SMD = 0.41, p = .034). No significant effects were found for other outcomes. Additional analyses showed that the effect on fluency of B2B + BS vs. BS increased over time during the two face-to-face sessions. Conclusion: Findings suggest that an RIT-based inspiration tool supports psychotherapeutic processes by reducing rigid thinking patterns, particularly at later stages of idea generation.

STUDY QUESTION: Is prenatal maternal stress (PNMS) in humans associated with alterations in the sexually differentiated reproductive axis structures in the offspring? SUMMARY ANSWER: PNMS, experienced by pregnant mothers exposed to a natural disaster in 1998, was associated with structural changes in hypothalamic-pituitary-axis (HPG) structures of 18.5-year-old offspring. WHAT IS KNOWN ALREADY: In a human prospective study, PNMS was associated with higher childhood BMI, which in turn predicted earlier menarche. Epidemiological studies have shown that maternal life event stress is associated with changes in gonadal morphology and function. STUDY DESIGN, SIZE, DURATION: A prospective study of mothers exposed to a severe ice storm in 1998 (N = 224) collected measures of PNMS (objective hardship and subjective distress). Offspring reproductive structures were assessed in early adulthood. PARTICIPANTS/MATERIALS, SETTING, METHODS: PNMS-exposed offspring (ICE; n = 39, 21 F, 18 M) and a control group (n = 31, 14 F, 17 M; born in 1997) were assessed at age 18.5 years. Participants underwent MRI. Using a novel approach, the structural integrity of the entire HPG axis was assessed using gold-standard manual delineation from their MRI scans. Ovarian antral follicles (2–10 mm) were also counted from MRI images. Salivary estradiol and testosterone were measured with ELISA. Data were analyzed with ANOVA and multiple regression. MAIN RESULTS AND THE ROLE OF CHANCE: The expected sex difference in hypothalamic volume (M > F) was detected in controls. Within ICE, the sex difference was observed at low, but not at high, levels of PNMS (objective and subjective). Greater objective hardship was associated with smaller hypothalamic volume in men. Similarly, pituitary volume was smaller in ICE men compared to control men. Within ICE, greater objective hardship was associated with smaller left testicular volume. Finally, compared to controls, the left ovary had more antral follicles and tended to be larger in ICE women. The group differences and associations between PNMS and HPG morphology were generally medium to large. LIMITATIONS, REASONS FOR CAUTION: The relatively small sample size may have limited our ability to detect small differences and to test interactions with gestational timing of prenatal stress exposure. In addition, the majority of women were taking oral contraceptives, and thus results must be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS: PNMS from a natural disaster may lead to functional changes in the human reproductive axis in adulthood. STUDY FUNDING/COMPETING INTEREST(S): Funding was provided by a grant from the Canadian Institutes of Health Research (CIHR, FRN 125892; to S.K., D.P.L., and J.C.P., and CIHR MOP 125892 to co-investigators S.K. S.L.J. was funded by a postdoctoral fellowship provided by the Fonds de Québec—Santé (FRQ-S). The funding sources were not involved in the collection, analyses, or interpretation of the data, or writing of the report. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.

Positive peer interactions are fundamental to children's social and academic development, yet the dynamic behaviors that support these interactions remain poorly understood. Smiling is one of the most frequent and socially functional behaviors, and when children respond to each other's smiles (smile synchrony) it provides a window into their engagement and connectedness. Although previous work has examined smile synchrony in dyadic settings, little is known about how it shapes perception of group activity or how individual backgrounds and relationships contribute to these dynamics. Here we show that smile synchrony serves as a behavioral marker of group interaction quality in children's collaborative activities. We analyzed facial expressions of 187 children in 34 groups during two everyday educational activities: listening to a story and discussing it together. Using automated smile detection and event-based analysis to quantify directional smile synchrony, we found that children with higher and more evenly distributed synchrony perceived more positive group climates, characterized by greater safety, contentment, inclusion, collaboration, and cohesion. Individual and dyadic factors further modulated these dynamics in activity-specific ways. During listening, synchrony increased with gender and national identity similarity and with perceived closeness to the smile emitter. During discussion, synchrony was heightened among extraverted children, those reporting greater group closeness, and friendship pairs. These findings reveal that smile synchrony captures meaningful variation in children's social engagement during real-world group interactions and reflects the interplay of personality, interpersonal relationships, and social identity. Our results suggest that smile synchrony represents an accessible behavioral marker for assessing peer interaction quality in collaborative learning environments.