Publications by authors named "Jeffrey Gassen"

Background: Although early adversity is now recognized as a major public health concern, it remains unclear if the effects of early-life stressors on disease biology and health differ by sex or stressor type. Because childhood stressors often covary, examining whether such stressors typically occur together (e.g.

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Although seasonal changes in physiology are well documented, little is known about how human immune and metabolic markers vary across seasons, and no studies have examined how stress → health biomarker associations differ across the year. To investigate these issues, we analyzed data from 2118 participants of the Midlife in the United States (MIDUS) study to determine whether there were differences in (a) levels of 19 immune and metabolic markers, and (b) the association between perceived stress and each biomarker across the year. Results of component-wide boosted generalized additive models revealed seasonal patterning for most biomarkers, with immune proteins generally peaking when days were shorter.

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In the current research, we used data from a sample of 16,327 menstrual cycle tracking app users to examine the association between menstrual cycle characteristics and sexual motivation tracked over 10 months of app use. Guided by past work that finds links between menstrual cycle characteristics related to conception risk and sexual motivation, we found that (a) between-women, shorter (r = - 0.04, p = 0.

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Many women experience sexual side effects, such as decreased libido, when taking hormonal contraceptives (HCs). However, little is known about the extent to which libido recovers after discontinuing HCs, nor about the timeframe in which recovery is expected to occur. Given that HCs suppress the activities of multiple endogenous hormones that regulate both the ovulatory cycle and women's sexual function, resumption of cycles should predict libido recovery.

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Despite decades of stress research, there still exist substantial gaps in our understanding of how social, environmental, and biological factors interact and combine with developmental stressor exposures, cognitive appraisals of stressors, and psychosocial coping processes to shape individuals' stress reactivity, health, and disease risk. Relatively new biological profiling approaches, called multi-omics, are helping address these issues by enabling researchers to quantify thousands of molecules from a single blood or tissue sample, thus providing a panoramic snapshot of the molecular processes occurring in an organism from a systems perspective. In this review, we summarize two types of research designs for which multi-omics approaches are best suited, and describe how these approaches can help advance our understanding of stress processes and the development, prevention, and treatment of stress-related pathologies.

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Women using hormonal contraceptives (HCs) exhibit numerous signs of chronic inflammation, including elevated C-reactive protein levels and greater risk of developing mood and autoimmune disorders. However, users and non-users of HCs often have similar circulating proinflammatory cytokine levels, making the mechanism of association unclear. One possible explanation for this paradox is that HC users exhibit differences in their inflammatory responses to psychosocial stress that, over time, could contribute to chronic inflammation and its pathologies.

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Many species exhibit seasonal patterns of breeding. Although humans can shield themselves from many season-related stressors, they appear to exhibit seasonal patterns of investment in reproductive function nonetheless, with levels of sex steroid hormones being highest during the spring and summer months. The current research builds on this work, examining the relationship between day length and ovarian function in two large samples of women using data from the Natural Cycles birth control application in each Sweden and the United States.

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Objectives: Tattooing is not an evolved behavior, but it may be a phenotypic gambit to highlight immunological health. Phenotypic gambits are traits or behaviors that appear costly but occur at high rates as a honing process of natural selection not constrained by genetics. Tattooing is an ancient practice that is increasing in popularity worldwide, but it involves wounding the body, which seems counterintuitive because it challenges the immune system and makes one more susceptible to infection.

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Testosterone levels in men appear to be prognostic of a number of disease outcomes, including severe COVID-19 disease. Testosterone levels naturally decline with age and are lower in individuals with a number of comorbidities and chronic conditions. Low testosterone may therefore be both a cause and a consequence of illness, including COVID-19 disease.

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Background And Objectives: Testosterone plays an important role in regulating male development, reproduction and health. Declining levels across the lifespan may reflect, or even contribute to, chronic disease and mortality in men.

Methodology: Relationships between testosterone levels and male mortality were analyzed using data from multiple samples of the cross-sectional National Health and Nutrition Examination Survey ( = 10 225).

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Baylor University established a surveillance system to assess the needs of students and faculty in isolation from SARS-CoV-2 as well as any longer-term symptoms. Overall, there were 309 responses between March 20 and May 19, 2021. A survey covering experience in isolation, symptoms, vaccination, and demographic characteristics was emailed to individuals on Day 7 of isolation; a follow-up health survey was sent 30 days later.

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Objectives: The selection pressures exerted by pathogens have played important roles in shaping the biology and behavior of animals, including humans. Immune systems recognize and respond to cues of infection or damage by coordinating cellular, humoral, and metabolic shifts that promote recovery. Moreover, animals also possess a repertoire of behavioral tools to help combat the threat of pathogens, often referred to as the behavioral immune system.

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In early-2020, the epidemiology of the SARS-CoV-2 virus was still in discovery and initial reports about the role of asymptomatic individuals were developing. The Waco COVID Survey was implemented in mid-2020 with targeted serological surveillance to assess relationships among risk factors and asymptomatic transmission in McLennan County, Texas, USA. Because large-scale random sampling of the population was not feasible, a targeted and repeated sampling of specific clustered groups of asymptomatic individuals was employed.

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Background: Pandemic fatigue describes a phenomenon whereby individuals experience a decrease in COVID-19 concern over time, despite their risk for infection remaining stable, or even increasing. Individual differences in the experience of pandemic fatigue may have important implications for people's adherence to public health recommendations.

Design And Methods: Using data collected from a large community cohort in McLennan County, TX, longitudinal changes in COVID-19-related concern, stress, and affect across three appointments separated by approximately 4 weeks (July-November 2020) were examined.

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Much research indicates that exposure to early life adversity (ELA) predicts chronic inflammatory activity, increasing one's risk of developing diseases of aging later in life. Despite its costs, researchers have proposed that chronic inflammation may be favored in this context because it would help promote immunological vigilance in environments with an elevated risk of infection and injury. Although intuitively appealing, the assumption that exaggerated inflammatory activity predicts favorable immunological outcomes among those exposed to ELA has not been tested.

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Thermoregulation is a complex, dynamic process involving coordination between multiple autonomic, endocrine, and behavioral mechanisms. In the context of infection, this intricate machinery generates fever, a process believed to serve vital functions in the body's defense against pathogens. In addition to increasing core temperature, infection can lead to changes in the dynamic fluctuations in body temperature over time.

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Despite concern about environmental protection, travelers often underestimate the contribution they may have to disease transmission to other species, as well as the risk of becoming infected themselves. Tourists in general tend to accept more physical risks when traveling than when at home, and much of this can be blamed on the temporary loss of situational awareness and loss of inhibition with a corresponding relaxed attitude toward safety. To better understand environmental attitudes and travel health knowledge and behaviors, a detailed survey of adult tourists was distributed on the island of St.

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Risk perception and consequently engagement in behaviors to avoid illness often do not match actual risk of infection, morbidity, and mortality. Unrealistic optimism occurs when individuals falsely believe that their personal outcomes will be more favorable than others' in the same risk category. Natural selection could favor overconfidence if its benefits, such as psychological resilience, outweigh its costs.

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Early life stress increases one's risk for health problems later in life, and many studies find that these effects are sex-differentiated. Here, we examined relationships between multiple sources of early life stress and adult immune function in humans across several functional assays. Adult participants provided retrospective information about their childhood (a) socioeconomic status, (b) household unpredictability, and (c) exposure to adverse experiences.

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Although the criminal justice system is designed around the idea that individuals are invariant in their responses to punishment, research indicates that individuals exhibit a tremendous amount of variability in their punishment sensitivity. This raises the question of why; what are the individual- and situation-level variables that impact a person's sensitivity to punishment? In the current research, we synthesize theory and research on inflammation, learning, and evolutionary biology to examine the relationship between inflammatory activity and sensitivity to punishment. These theories combine to predict that inflammatory activity - which is metabolically costly and reflects a context in which the net payoff associated with future oriented behaviors is diminished - will decrease sensitivity to punishment, but not rewards.

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Winter is characterized by stressful conditions which compromise health and render animals more vulnerable to infection and illness than during other times of the year. Organisms are hypothesized to adapt to these seasonal stressors by increasing investment in immune function in response to diminished photoperiod duration. Here, we examined this hypothesis in a sample of healthy human participants.

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Here, we propose a novel theoretical model linking present-focused decision-making to the activities of the immune system. We tested our model by examining the relationship between inflammatory activity - in vivo and in vitro - and decision-making characterized by impulsivity, present focus, and an inability to delay gratification. Results support our model, revealing that inflammation predicts these outcomes even after controlling for factors that may contribute to a spurious linkage between them.

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The human menstrual cycle is characterized by substantial variability both within and between women. Here, we sought to account for such variability by examining whether human menstrual cycle frequency varies as a function of the projected fitness payoffs associated with investment in mating effort. We used structural equation modeling to test the prediction that women whose environmental conditions or life histories favor heavier investment in mating effort would have shorter, more regular cycles.

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Here, we present a mechanistically grounded theory detailing a novel function of the behavioral immune system (BIS), the psychological system that prompts pathogen avoidance behaviors. We propose that BIS activity allows the body to downregulate basal inflammation, preventing resultant oxidative damage to DNA and promoting longevity. Study 1 investigated the relationship between a trait measure of pathogen avoidance motivation and in vitro and in vivo proinflammatory cytokine production.

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