Bidirectional Relationship Research Articles

The ABCDs of nutritional assessment in infectious diseases research

Abstract Malnutrition is the most common acquired cause of immunodeficiency worldwide. Nutritional deficiencies can blunt both the innate and adaptive immune response to pathogens. Furthermore, malnutrition is both a cause and consequence of infectious diseases. The bidirectional relationship between infectious diseases and undernutrition, as well as the inflammatory milieu of infectious diseases, can complicate nutritional assessment. This article aims to provide clinicians and researchers with an overview of commonly used tools to assess nutritional status, with a particular emphasis on their use in the context of infectious diseases. This includes anthropometric, biochemical, clinical/physical, and dietary assessments to screen and evaluate undernutrition, diet quality, and food insecurity effectively.

The impact of oral health on depression: A systematic review.

As of 2020, about 21% of adults in the United States have a diagnosable mental health disorder, excluding substance use and developmental disorders. Depression, predicted by the WHO to be the leading cause of disease burden by 2030, is linked to various systemic conditions and has been associated with poor oral health. Both behavioral factors, like poor dental hygiene and irregular visits, and biological mechanisms, such as changes in salivary immunity, contribute to this connection, which impacts overall well-being and quality of life. This systematic review aims include: (1) Does tooth loss affect depression? (2) Does oral pain, such as that experienced during chewing and speaking, impact depression? (3) Does oral functionality, including chewing and speaking, influence depression? (4) Does overall oral health affect depression? We conducted a systematic search of PubMed, EBSCO host, Medline, and Google Scholar databases from January 2000 to June 2024 using relevant keywords. Studies examining the impact of oral health parameters (tooth loss, oral pain, oral functionality, overall oral health) on depression were included. Articles were included if (1) full text manuscripts in English were available, (2) the study described the association of oral health and depression, and (3) the independent value was an oral related factor and the dependent value was depression. The following were excluded from our analysis: (1) any articles where oral factors were not the independent value, (2) systematic reviews, (3) case reports, and (4) duplicate studies among our databases. Thirty-one studies met the inclusion criteria. Tooth loss, oral pain, and impaired oral functionality were consistently associated with increased depressive symptoms across the included studies. Greater tooth loss was linked to higher odds of both onset and progression of depression. Oral pain exacerbated depressive symptoms, while difficulties in chewing or speaking were associated with elevated risks of depression. There is a bidirectional relationship between oral health and depression, highlighting the urgent need for comprehensive public health initiatives. Integrating oral health assessments into routine medical care, and developing targeted interventions are crucial steps to mitigate the impact of poor oral health on mental health outcomes.

Neuroimmune cross-talk in heart failure.

Heart failure (HF) is characterized by autonomic nervous system (ANS) imbalance and low-grade chronic inflammation. The bidirectional relationship between the ANS and immune system (IS) is named "neuroimmune cross-talk" (NICT), and is based on common signaling molecules, receptors, and pathways. NICT may be altered in HF, and neuroinflammation seems to be a main driver of HF progression. In HF, heightened sympathetic nerve activity triggers inflammatory cascades that lead to cardiomyocyte death and myocardial interstitial fibrosis. Concurrently, parasympathetic withdrawal may impair the cholinergic anti-inflammatory pathway, with a less effective immune response to infections or inflammatory events. Additionally, microglial activation and inflammatory molecules contribute to autonomic imbalance by acting on central nuclei and peripheral visceral feedbacks, which in turn promote adverse cardiac remodeling, HF decompensation, and potentially life-threatening arrhythmias. Therefore, neuroinflammation has been identified as a potential target for treatment. Pharmacological antagonism of the neurohormonal system remains the cornerstone of chronic HF therapy. While some drugs used in HF management may have additional benefits due to their anti-inflammatory properties, clinical trials targeting inflammation in patients with HF have so far produced inconclusive results. Nevertheless, considering the pathophysiological relevance of NICT, its modulation seems an appealing strategy to optimize HF management. Current research is therefore investigating novel pharmacological targets for anti-inflammatory drugs, and the immunomodulatory properties of denervation approaches and bioelectronic medicine devices targeting NICT and neuroinflammation in HF. A deeper understanding of the complex relationship between the ANS and IS, as outlined in this review, could therefore facilitate the design of future studies aimed at improving outcomes by targeting NICT in patients with HF.

Work Satisfaction and Its Relationship with Burnout and Its Consequences, Using a Structural Model, in Air Cabin Crew Members

Burnout is an emerging socio-labor phenomenon, where this problem is particularly relevant in airline cabin crew members, who face important psychosocial demands and difficult working conditions. This study aimed to analyze job satisfaction and its relationship with burnout and its consequences (family–work conflict (FWC), work–family conflict (WFC), and psychosomatic disorders), through structural models. The sample consisted of 732 workers in the aeronautical sector (204 men/28% and 528 women/72%), aged between 19 and 53 years (M = 33.56, dt = 6.62). The hypotheses were tested using a path model. The selected hypothesized model [where work satisfaction is associated according to the relationships established burnout model showed an adequate fit of the data, including a mediating role of feelings of guilt in the relationship between burnout and FWC (where FWC was associated with WFC and psychosomatic disorders). The findings of this study provide further insight into the problematic experience and development of burnout in airline cabin crews, in turn providing new evidence on the bidirectional and reciprocal relationships of FWC.

RGB-D Data Compression via Bi-Directional Cross-Modal Prior Transfer and Enhanced Entropy Modeling

RGB-D data, being homogeneous cross-modal data, demonstrates significant correlations among data elements. However, current research focuses only on a unidirectional pattern of cross-modal contextual information, neglecting the exploration of bidirectional relationships in the compression field. Thus, we propose a joint RGB-D compression scheme, which is combined with Bi-directional Cross-modal Prior Transfer (Bi-CPT) modules and a Bi-directional Cross-modal Enhanced Entropy (Bi-CEE) model. The Bi-CPT module is designed for compact representations of cross-modal features, effectively eliminating spatial and modality redundancies at different granularity levels. In contrast to the traditional entropy models, our proposed Bi-CEE model not only achieves spatial-channel contextual adaptation through partitioning RGB and depth features but also incorporates information from other modalities as prior to enhance the accuracy of probability estimation for latent variables. Furthermore, this model enables parallel multi-stage processing to accelerate coding. Experimental results demonstrate the superiority of our proposed framework over the current compression scheme, outperforming both rate-distortion performance and downstream tasks, including surface reconstruction and semantic segmentation. The source code will be available at https://github.com/xyy7/Learning-based-RGB-D-Image-Compression .

A Deep Learning Method to Integrate extracelluar miRNA with mRNA for cancer studies.

Extracellular miRNAs (exmiRs) and intracellular mRNAs both can serve as promising biomarkers and therapeutic targets for various diseases. However, exmiR expression data is often noisy, and obtaining intracellular mRNA expression data usually involves intrusive procedures. To gain valuable insights into disease mechanisms, it is thus essential to improve the quality of exmiR expression data and develop non-invasive methods for assessing intracellular mRNA expression. We developed CrossPred, a deep-learning multi-encoder model for the cross-prediction of exmiRs and mRNAs. Utilizing contrastive learning, we created a shared embedding space to integrate exmiRs and mRNAs. This shared embedding was then used to predict intracellular mRNA expression from noisy exmiR data and to predict exmiR expression from intracellular mRNA data. We evaluated CrossPred on three types of cancers and assessed its effectiveness in predicting the expression levels of exmiRs and mRNAs. CrossPred outperformed the baseline encoder-decoder model, exmiR or mRNA-based models, and variational autoencoder models. Moreover, the integration of exmiR and mRNA data uncovered important exmiRs and mRNAs associated with cancer. Our study offers new insights into the bidirectional relationship between mRNAs and exmiRs. The datasets and tool are available at https://doi.org/10.5281/zenodo.13891508. Supplementary data are available at Bioinformatics online.

A scoping review of food consumer aspects in transitioning to a safe and just agrifood system

Abstract The agrifood system holds the key to identifying potential transformative pathways to achieve prosperity for all within the limits of the planet's natural resources, thereby fostering a safe and just operating system (SJOS) for future generations. The agrifood system is currently not on the right track to meet this ambition. Food-consumer processes such as preference shifts toward healthy diets and substantial reductions in food losses and waste could help to avoid severe environmental degradation and decrease overall mortality, although it remains unclear whether such transitional developments are entirely compatible with socially responsible thresholds. In this paper, we conduct a scoping review approach to map the evidence on the underlying drivers of such demand-side processes in the context of a SJOS with the aim to provide insights on how to transform the EU agrifood system. This review specifically examines how consumer aspects influence the SJOS, rather than exploring the bidirectional relationship. We used a scoping review approach to select relevant studies. The selected papers were subjected to quantitative and qualitative analyses. As a result, we extract insights and draw lessons from the role of food-consumer processes in the transition toward a more SJOS for the agrifood system.

The Impact of Neutrophil-to-High-Density Lipoprotein Ratio and Serum 25-Hydroxyvitamin D on Ischemic Heart Disease

Background: This study describes the complex association between the neutrophil-to-high-density lipoprotein cholesterol ratio (NHR), 25-hydroxyvitamin D (25(OH)D) levels, and cardiovascular disease (CVD), such as stable ischemic heart disease (IHD), ST elevation myocardial infarction (STEMI), non–ST-segment elevation myocardial infarction (NSTEMI), and unstable angina (UA). Methods: The serum 25(OH)D concentration and NHR values were analyzed in groups of patients with chronic coronary syndrome (CCS) and acute coronary syndrome (ACS). The severity of coronary artery atherosclerosis was determined using the Coronary Artery Surgery Study (CASS) scale. Results: Significant differences in 25(OH)D and NHR concentrations were observed between CCS and (ACS)/STEMI patients (p < 0.01). Higher 25(OH)D concentrations were associated with the diagnosis of CCS, and higher NHR values with the diagnosis of ACS/STEMI. The NHR threshold for ACS was set at 0.10 (p < 0.001). Patients without significant coronary artery stenosis showed significantly higher 25(OH)D levels and lower NHR values (p < 0.01). Conclusions: The significant correlation between 25(OH)D, HDL, and the NHR suggests that vitamin D, through its influence on inflammatory processes and lipid metabolism, may play a role in the pathogenesis of chronic and acute coronary syndromes. The suggested bidirectional relationship between the NHR and 25(OH)D and the role of the NHR as a predictor of vitamin D levels require further well-designed studies.

A multiple behaviour temporal network analysis for health behaviours during COVID-19.

The aim of this study was to examine the temporal dynamics of multiple health behaviours (physical activity, alcohol consumption, healthy eating, cigarette consumption, recreational drug use, vaping), and pandemic-related health behaviours (e.g., hand washing, physical distancing) using network psychometrics. The International COVID-19 Awareness and Responses Evaluation (iCARE) study is an international multi-wave observational cohort study of public awareness, attitudes, and responses to public health policies implemented to reduce the spread of COVID-19 on people around the world. A sub-sample of longitudinal data from Canadians (n = 254) was analysed across four waves (February-July 2020). We used temporal network models to fit temporal networks, contemporaneous networks, and between-subject networks from items within the iCARE survey. Positive temporal associations were observed between physical activity and healthy eating, and a bidirectional relationship was evident between outdoor mask use and vaping. A contemporaneous network revealed positive associations between consumption behaviours (vaping, cigarette use, alcohol use, and recreational drug use), and negative associations between physical activity and drug use, and healthy eating and cigarette use. Health behaviours are interconnected and can be modelled as networks or behavioural systems. The application of temporal network analysis to the study of multiple health behaviours is well suited to address key research questions in the field such as 'how do multiple health behaviours co-vary with one another over time'. Future research using time series data and measuring affective and cognitive mediators of behaviour, in addition to health behaviours, has the potential to contribute valuable hypothesis-generating insights.

Subjective well-being and attitudes toward outgroup members

There is a large body of literature on the effect of negative attitudes toward outgroup members on target individuals and groups. However, less attention was devoted to their effects on those who hold these attitudes. The current study hypothesized that there would be a bidirectional relationship between subjective well-being and attitudes toward outgroup members. In Study 1, data from the Integrated Values Surveys, the Ecology-Culture Dataset, and the World Happiness Report 2022 were used. In Study 2, a random intercept cross-lagged panel model was implemented using longitudinal data over a six-year period from the GESIS Panel (n = 6783 people living in Germany). Results of Study 1 demonstrated a significant negative relationship between subjective well-being and negative attitudes toward outgroup members both at the country level (118 countries) and at the individual level (663,965 participants in 120 countries around the world). In Study 2, a random intercept cross-lagged panel model revealed significant within-person reciprocal relations between life satisfaction and negative attitudes toward refugees. This study provides evidence for a bidirectional relationship between subjective well-being and negative attitudes toward outgroup members.

Exploring the effects of multi-dimensional geographic environment on daily sleep and physical activity based on the Actigraph data

Understanding the interplay between people’s daily sleep and physical activity and how geographic environment influences them are important for developing healthy cities. However, such research has been limited. This study aims to explore the bidirectional and nonlinear relationship between daily sleep and physical activity, and further investigate the comprehensive influences of multi-dimensional geographic environment on these health behaviors. Based on the objective data on sleep and physical activity over seven consecutive days using wrist-based accelerometers in Beijing, China, we developed a series of models to analyze the mutual influences between people’s daily sleep and physical activity, and employed the generalized additive model (GAM) to examine their potential nonlinear relationships and how geographic environment – including meteorological conditions, built environment, and social environment – influences them. The results show that sleep and physical activity exhibit notable bidirectional relationship. Moderate-to-vigorous physical activity (MVPA) is observed to improve sleep quality, but it decreases sleep duration. In contrast, total sleep time (TST) exhibits an inverted U-shaped pattern with both MVPA and total step counts, with the optimal sleep duration at 5 hours. Furthermore, meteorological factors, built environment characteristics, and social environment have significant linear or nonlinear effects on people’s daily sleep and physical activity. The outcomes of this study offer valuable insights for enhancing residents’ health and developing healthy cities.

Evidence from Aphasia Suggests a Bidirectional Relationship between Inner Speech and Executive Function

Research over the past several decades has revealed that non-linguistic cognitive impairments can appear alongside language deficits in individuals with aphasia. One vulnerable cognitive domain is executive function, an umbrella term for the higher-level cognitive processes that allow us to direct our behavior towards a goal. Studies in healthy adults reveal that executive function abilities are supported by inner speech, the ability to use language silently in one's head. Therefore, inner speech may mediate the connection between language and executive function deficits in individuals with aphasia. Here, we investigated whether inner speech ability may link language and cognitive impairments in 59 adults with chronic, post-stroke aphasia. We used two approaches to measure inner speech: one based on internal retrieval of words and one based on internal retrieval plus silent manipulation of the retrieved phonological forms. Then, we examined relationships between these two approaches to measuring inner speech and five aspects of executive function ability: response inhibition, conflict monitoring/resolution, general task-switching ability, phonological control, and semantic control. We also looked for dissociations between inner speech ability and executive function ability. Our results show tentative relationships between inner speech (across multiple measurement approaches) and all aspects of executive function except for response inhibition. We also found evidence for a double dissociation: many participants show intact executive function despite poor inner speech, and vice versa, so neither process is strictly reliant on the other. We suggest that this work provides preliminary evidence of a bidirectional relationship between inner speech and executive function: inner speech supports some aspects of executive function via internal self-cueing and certain aspects of executive function support performance on complex inner speech tasks.

Bidirectional Relations Among Maternal Positive Emotion, Infant Positive Emotionality, and Infant Physiological Regulation Across the First 18 Months of Life.

Respiratory sinus arrhythmia (RSA), a marker of self-regulation, has been linked to developmental outcomes in young children. Although positive emotions may have the potential to facilitate physiological self-regulation, and enhanced self-regulation could underlie the development of positive emotions in early childhood, the relation between positive emotions and physiological self-regulation in infancy has been relatively overlooked. The current study examined the bidirectional associations among maternal positive emotion, infant positive emotionality, and infant resting RSA across the first 18 months of life. We used data from the Longitudinal Attention and Temperament Study (LanTs; N=309 in the current analysis) to test the within- and between-person relations of study variables over time using a random-intercepts cross-lagged panel model. We found that infants with higher overall levels of positive emotionality also displayed greater resting RSA, and their mothers exhibited higher levels of positive emotion. However, there were negative cross-lagged associations within-person; higher than average infant positive emotionality predicted lower levels of infant resting RSA at the subsequent timepoint during early infancy, whereas higher than average infant RSA subsequently predicted decreased levels of infant positive emotionality later in infancy. Results highlight the importance of considering transactional relations between positive emotion and physiological self-regulation in infancy.

Reciprocal relations between acute interpersonal negative life events and acute alcohol use: An examination of the 24 h preceding suicide attempts among hospitalized patients

ObjectiveTo examine the within-person relations between acute alcohol use and interpersonal negative life events (INLEs) in the 24 h preceding suicide attempts. MethodParticipants were 151 adult patients (67.55 % female; M age = 36.00) who were hospitalized within 24 h of a suicide attempt. Participants completed the Timeline Follow-back for Suicide Attempts interview to gather information about hourly events for the 24 h preceding their suicide attempt. Hierarchical logistic models were estimated to examine the influence of acute INLEs on next-hour alcohol use and acute alcohol use on next-hour INLEs. Biological sex and chronic alcohol use (past year) were evaluated as potential moderators. ResultsOverall, acute alcohol use was associated with increased odds of next-hour INLEs and acute INLEs were associated with increased odds of next-hour alcohol use. Moderator analyses indicated that the influence of alcohol use on INLEs increased as participants' level of chronic alcohol use decreased, and relations did not vary by biological sex. ConclusionsThere is a bidirectional relation between INLEs and alcohol use in the hours preceding suicide attempts. Understanding that these within-person interrelations may differ in strength depending on one's level of chronic alcohol use has practical utility for providers tasked with clinical decision making.

Mental Health Implications of Weight Loss Medications: A Narrative Review

Obesity and mental illness are commonly encountered clinical issues that nurse practitioners manage. A bidirectional and complex relationship exists between these 2 clinical concerns, with management of either condition affecting the other. Individuals with obesity and/or mental illness experience disparities in health outcomes. Even among individuals without mental health conditions, pharmacologic management of obesity can have mental health adverse effects. This review discusses current weight loss medications and their mental health implications. Nurse practitioners caring for individuals with obesity and/or mental health conditions can benefit from considering the effect of each medication on physical and mental health outcomes.

Quality of Life in Children With Chronic Health Conditions and Its Contribution to Unmet Supportive Care Needs of Families.

While theoretical models have established the bidirectional relationship between health and wellbeing of parents and children with chronic health conditions (CHCs), previous work has predominantly emphasised the impact of parent functioning on child outcomes. This study examines how quality of life (QoL) domains in children with CHCs are associated with unmet supportive care needs (SCN) of their parents and explores whether these associations vary by health condition. Parents of children with congenital heart disease (CHD), type 1 diabetes (T1D) and cancer diagnosed before the age of 12 years and receiving treatment within the last 5 years were eligible. Parents recruited through charity organisations and social media platforms completed a secure, online survey via Qualtrics. The PedsQL examined child QoL across four dimensions: physical, emotional, social and school functioning. A 34-item survey assessed parents' unmet SCN in the previous month across six need domains (e.g., care and informational). Linear regressions examined associations between child QoL and unmet SCN domains and moderation analyses determined whether associations varied as a function of CHC. The study included 186 parents (age range 25-56 years) of children diagnosed with various CHCs (52% CHD; 27% T1D, 21% cancer). The child's emotional functioning was inversely related to all unmet SCN domains, social functioning was inversely related to three domains (physical and social; support; financial), school functioning was inversely related to two domains (physical and social; care), and child's physical functioning was not associated with any SCN domains. Only the association between child school functioning and unmet care needs was significantly moderated by CHC type (p < 0.05). Poorer emotional functioning in children with a CHC is a key factor in determining parents unmet SCN. Larger studies are required to replicate these findings and inform design of interventions addressing QoL and unmet SCN in families of children with common CHCs.

Causal relationships between epilepsy and the microstructure of the white matter: A Mendelian randomization study.

To examine the causal bidirectional relationships between epilepsy and microstructural changes in the white matter (WM). A genome-wide association study meta-analysis of the International League Against Epilepsy Consortium on Epilepsy and 360 WM imaging-derived phenotypes (IDPs) from the UK Biobank was used for the analysis. Genetic correlation analyses were conducted based on summary statistics of various "IDP-epilepsy" pairs for 2-sample Mendelian randomization (MR) analysis to explore the causal relationships. We used the inverse variance weighted (IVW) method as the primary MR analysis approach, and conducted sensitivity analyses for pleiotropy and heterogeneity. Forward MR analysis revealed that alterations in the 16 WM IDPs increased the risk of epilepsy (q value < 0.05). Changes in the 38 WM IDPs were associated with a decreased risk of epilepsy (q value < 0.05). In the reverse analysis, seizures from all epilepsy types changed 5 WM IDPs, whereas seizures from juvenile myoclonic epilepsy altered 11 WM IDPs (q value < 0.05). This study revealed causal associations between changes in the WM microstructure and epilepsy subtypes. These findings offer new directions for early prevention and treatment of epilepsy.

Pain and development: interacting phenomena

Abstract For decades, clinicians and researchers have observed bidirectional relationships between child development and the pain experience in childhood. Pain in childhood is an inherently developmental phenomenon, embedded in an iterative, time-dependent process that reflects individual biological, behavioral, social, psychological, and environmental characteristics that unfold across the early life span. Childhood pain can have wide ranging effects on brain development in ways that contribute—for better and worse—to social, emotional, and cognitive well-being in childhood and on into adulthood. Atypical trajectories of development in the context of disorders such as autism, cerebral palsy, ADHD, and mood/anxiety disorders also contribute to unique childhood pain experiences. In this paper, pain will be considered as a determinant of development, and conversely development will be considered as a key determinant of a child's pain experience. We will discuss how intersectional identities (eg, gender, race, socioeconomic status) and associated social, structural, systemic, and physical environments influence the relationship between development and pain. Finally, we will identify what might be needed to think “developmentally” in ways that extend from the “bench side” in the lab to the “curb side” in the community, integrating a developmental perspective into research and clinical practice to achieve health accessibility and equity in pain care for all children across the developmental spectrum.

Transforming the diabetes outcomes for people with mental illness

AbstractThere is a complex bidirectional relationship between diabetes and mental illness, where diabetes is associated with an increased prevalence of a range of mental disorders and several mental illnesses increase the risk of diabetes. The reasons why people with mental illness are at higher risk of diabetes and vice versa are multifactorial. When diabetes and mental illness occur together, the outcomes for both conditions are worsened, and the co‐morbidity places a higher burden on the individual living with the conditions.Severe mental illness is associated with a twofold increased risk of diabetes, and the onset of diabetes is approximately 10 years earlier in people with mental illness than in the general population. Health behaviour interventions to reduce the incidence of diabetes may be less effective than previously thought. However, trials on obesity drugs, particularly glucagon‐like peptide‐1 receptor agonists, are showing promise. Diabetes care for people with severe mental illness seems to have improved in the past decade. Interventions have been developed to address the unique challenges of living with severe mental illness and diabetes.Depression is twice as common in people with diabetes. Depression increases the risk of diabetes and vice versa. Although general population risk factors for depression apply to people with diabetes, diabetes‐specific risk factors include the development of complications and insulin use in people with type 2 diabetes. Managing depression includes efforts to prevent depression, timely diagnosis and treatment with psychological or pharmacological treatments.Health care professionals have a responsibility to ensure that people with mental illness and diabetes are not disadvantaged.

Bidirectional relationships between chronotype and sleep hygiene in children with and without parental history of alcohol use disorder.

Children with evening chronotype may be at risk for insufficient sleep because their chronotype makes it difficult to sustain healthy sleep habits. We evaluated bidirectional relationships between chronotype and sleep hygiene. Two hundred forty-six children (n=246 at T1, n=200 at T2, n=147 at T3), with a mean age of 9.9 (SD=1.4) at T1, participated in a longitudinal study on sleep and substance use. Participants either had a parental history of alcohol use disorder or were matched controls. The Adolescent Sleep Hygiene Scale measured sleep hygiene. Chronotype was measured using the Morningness/Eveningness Questionnaire. We used random intercept cross-lagged panel models to examine longitudinal relations between chronotype and sleep hygiene across three time points, each approximately 1 year apart. Chronotype at T1 predicted sleep hygiene at T2 (b=0.38, p<.05). Chronotype at T2 predicted sleep hygiene at T3 (b=0.38, p<.05). T1 Sleep Hygiene predicted chronotype at T2 (b=0.27, p<.05). T2 Sleep Hygiene predicted chronotype at T3 (b=0.24, p<.05). Chronotype also predicted itself over time (T1-T2: b=0.31, p<.05; T2-T3: b=0.31, p<.05). Sleep hygiene did not predict itself at future time points. Parental history of alcohol use disorder did not predict sleep hygiene or chronotype. There is a bidirectional relationship between chronotype and sleep hygiene; more eveningness predicts poorer sleep hygiene at a later time point, and poorer sleep hygiene predicts more eveningness later. Sleep hygiene is not stable over time and may be a more modifiable target for public health interventions than chronotype.