Small Effect Sizes Research Articles

Benchmarking sample pooling for epigenomics of natural populations.

DNA methylation (DNAm) is a mechanism for rapid acclimation to environmental conditions. In natural systems, small effect sizes relative to noise necessitates large sampling efforts to detect differences. Large numbers of individually sequenced libraries are costly. Pooling DNA prior to library preparation may be an efficient way to reduce costs and increase sample size, yet there are to date no recommendations in ecological epigenetics research. We test whether pooled and individual libraries yield comparable DNAm signals in a natural system exposed to different pollution levels by generating whole-epigenome data from two invasive molluscs (Corbicula fluminea, Dreissena polymorpha) collected from polluted and unpolluted localities (Italy). DNA of the same individuals were used for pooled and individual epigenomic libraries and sequenced with equivalent resources per individual. We found that pooling effectively captures similar genome-wide and global methylation signals as individual libraries, highlighting that pooled libraries are representative of the global population signal. However, pooled libraries yielded orders of magnitude more data than individual libraries, which was a consequence of higher coverage. We would therefore recommend aiming for a high initial coverage of individual libraries (15×) in future studies. Consequently, we detected many more differentially methylated regions (DMRs) with the pooled libraries and a significantly lower statistical power for regions from individual libraries. Computationally pooled data from the individual libraries produced fewer DMRs and the overlap with wet-lab pooled DMRs was relatively low. We discuss possible causes for discrepancies, list benefits and drawbacks of pooling, and provide recommendations for future epigenomic studies.

Vocabulary learning in EMI courses: A longitudinal study of Chinese university students over a term

This paper reports the results of research investigating EMI students' vocabulary gain over a term of study (10–12 weeks) at a university in China. Though vocabulary learning is usually considered by stakeholders to be an underlying goal of EMI, relatively little empirical research systematically explores EMI students' vocabulary gains. We examined EMI students' learning outcomes of receptive and productive general and academic vocabulary, as well as multi-word units. Data was collected from 114 students taking EMI courses in various subject areas using a range of vocabulary knowledge tests, including the vocabulary levels test (VLT), the productive vocabulary levels test (PVLT) and a multi-word units test. Findings reveal some significant gains in students' vocabulary knowledge but with small effect sizes. Significant vocabulary gain was found in students’ general vocabulary receptive and productive knowledge as well as in their productive academic vocabulary and knowledge of multi-word units. Their productive vocabulary knowledge was considerably lower at both data collection points, even though students showed more improvement in productive than receptive vocabulary. Greater vocabulary gains were observed in students who attended more EMI classes. The results suggest that vocabulary gain might not be taken for granted as a by-product of EMI.

Self-Reported Perceptions of Patients and Staff on Participation and Verbal and Social Interactions in High-Security Forensic Psychiatric Care in Sweden.

Studies suggest that experiences of patient participation, as described by both patients and staff, are associated with a significant caring relationship of high quality. This study aimed to investigate staffs' and patients' self-reported perceptions on participation and the frequency and importance of verbal and social interactions in high-security forensic psychiatry. The questionnaire Verbal and Social Interactions (VSI) was used together with the subscale Participation from Quality in Psychiatric Care (QPC). The study was conducted at a large forensic psychiatric clinic in Sweden. Staff and patients rated the frequency of VSI differently while reporting the same perceived degree of patient participation. All categories of VSI were significantly correlated with perceived level of participation with medium or small effect size for the patients. Patients' perceived participation seems to depend on verbal and social interaction within the specific categories 'Showing interest in the patients' feelings, experiences, and behavior' and 'Helping the patients establish structure and routines in their everyday life'. There was, however, a negative association for the latter. The results give a better understanding of what kind of interactions that affect patients' perceived level of participation. Patient participant is a prioritised area for development in forensic psychiatry. The study contributes to a better understanding of what types of interactions that affect the perceived level of participation, while at the same time, it shows important similarities and differences between patient and staff perspectives.

Developing and evaluating the extended epistemic vigilance framework

AbstractIn science education, epistemic vigilance plays a key role in the development of students' critical thinking by supporting students' abilities to evaluate the expertise level of the source and to evaluate the claim itself, using rigorous scientific standards and appropriate argumentation heuristics. Based on previous studies, which suggested two aspects of epistemic vigilance—reflecting the source of information and the claim that is made—we developed the Extended Epistemic Vigilance Framework (EEVF) that includes an additional aspect of evaluating the receiver. In an empirical exploratory pilot study, we evaluated the reliability and validity of an EEVF‐based category system and investigated to what extent the EEVF can be used to characterize changes in biology graduate students' epistemic vigilance after participating in a critical thinking course. Results show that the EEVF‐based category system includes reliable and valid categories for identifying students' epistemic vigilance. A statistically significant increase with a small effect size was found in students' epistemic vigilance regarding the reliability of the source and the references used to support the claim following their participation in the critical thinking course. However, a statistically significant decrease with a small effect size was found regarding the awareness of the aspects of the one‐sidedness of the claim, the context of the claim, and cognitive biases and socioemotional influences on the receiver. In general, these findings indicate that the EEVF offers an improved framework to analyze students' epistemic vigilance more comprehensively.

Ecological-Dynamic Approach vs. Traditional Prescriptive Approach in Improving Technical Skills of Young Soccer Players.

Background: This study contributes to expanding the existing literature on learning technical skills in youth soccer by comparing the effectiveness of different training approaches in the development of passing skills. The ecological-dynamic approach, which emphasizes the continuous and adaptive interaction between the athlete and the environment, is analyzed in comparison to the traditional prescriptive approach, which relies on predefined techniques and exercises. The aim of the study is to determine which of the two approaches is more effective in improving the performance of young soccer players. Methods: Thirty players (age 12 ± 1.2 years) were randomly assigned to two groups: the ecological-dynamic group (ECG) and a control group (CON). Both groups underwent an eight-week training program with equal sessions. The ECG group's training focused on adjusting constraints like the learning environment, game rules, and visual restrictions to boost adaptability and problem-solving skills. The CON group followed a traditional prescriptive approach with specific instructions, goal setting, immediate feedback, and structured exercise progression. Passing abilities were evaluated before and after the program using the Loughborough Soccer Passing Test, with a retention test administered five weeks later. Descriptive statistics, including mean values and percentage improvements, were used. A repeated measures ANOVA compared differences between the groups. Results: The analysis revealed a significant Occasion × Group interaction for all performance variables, indicating that the ECG group experienced greater improvements than the CON group. Specifically, the ECG group showed significant reductions in Trial Time (p = 0.001, ηp2 = 0.6), Penalty Time (p = 0.016, ηp2 = 0.4), and Overall Performance (p = 0.011, ηp2 = 0.8) from pre-test to post-test. However, these improvements did not persist into the retention test (p = 0.131, p = 0.792, and p = 0.192, respectively). The CON group also improved significantly in Trial Time (p = 0.003), Penalty Time (p = 0.002), and Overall Performance (p = 0.001) from pre-test to post-test, but with smaller effect sizes and no sustained gains at retention. Conclusions: The ecological-dynamic approach (EDG) has proven to be more effective in enhancing passing skills compared to the traditional prescriptive approach (CON). Although both methods led to performance improvements, the EDG group achieved more significant progress.

Why Students Cannot Easily Integrate Component Skills: An Investigation of the Composition Effect in Programming

Programming skills are increasingly important to the current digital economy, yet these skills have long been regarded as challenging to acquire. A central challenge in learning programming skills involves the simultaneous use of multiple component skills. This article investigates why students struggle with integrating component skills—a challenge called the composition effect. This effect was first studied in learning mathematics, and findings in that area have led to more effective instruction in mathematics. In the current work, we systematically investigate the nature of the composition effect in novice code tracing through a classroom study in a university-level introductory programming course. We designed a set of problems that require integrating component skills, along with matched problems that use the same component skills separately. The composition effect was defined as the performance difference between these two types of problems. We further singled out errors that were committed in integration problems but not in the matched problems and conducted qualitative coding to categorize these errors. Statistical analyses produced three main findings. First, we found a robust composition effect across problems and students, mostly with small or medium effect sizes. Second, we identified two potential sources of errors for this composition effect: conceptual misunderstandings of how to integrate component skills and process errors resulting from slips related to cognitive load challenges. In particular, additional conceptual knowledge often appears to be needed when component skills are integrated in specific ways. Moreover, the primary source appears to be misunderstandings of how skills integrate. Composition effects may not generalize across topics, which suggests that domain topics may serve as the conceptual basis for the composition effect. Third, we found stable individual differences in susceptibility to the composition effect in both overall and finer-grained levels. Our findings provide implications for building theories that may generally explain challenges in learning complex skills and may result in practical designs for skill integration enhanced curricula and instruction to foster student mastery in computing education.

Association between sleep bruxism and snoring in adults: An observational study

ObjectiveThis study evaluated the association between sleep bruxism and snoring. Additionally, the associations between sleep bruxism and age, sex, body mass index, sleep structure, sleep quality, and sleepiness were evaluated. MethodsAdults suspected of having sleep disorders (n = 61) underwent single-night video polysomnography according to the American Academy of Sleep Medicine criteria. Validated questionnaires were used to assess sleepiness and sleep quality, and clinical examinations were performed to document weight and height. Jamovi software was used for statistical analysis. Logistic regression analyses of the different sleep stages—REM sleep, NREM sleep, and total sleep time—were conducted. ResultsNo association was found between sleep bruxism and snoring (P > 0.31), with a small effect size (V = 0.171). However, the snore index was found to influence the rhythmic masticatory muscle activity index during REM sleep, with an odds ratio of 1.018 (95 % CI: 1.005 to 1.03; P = 0.05). Moreover, logistic regression showed that the desaturation index presented an odds ratio of 5.01 (95 % CI: 0.96 to 26.13; p = 0.056), with a medium effect size (>3.5). Sleep bruxism was not associated with age, sex, body mass index, or other sleep variables. ConclusionSnoring appears to be associated with bruxism during REM sleep. No associations were found between sleep bruxism and sex, age, or body mass index. This lack of association underscores the complexity of sleep bruxism and snoring and highlights the need for further research. Concerning sleep architecture, only desaturation episodes were associated with bruxism during REM sleep. Neither sleep quality nor sleepiness was associated with sleep bruxism.

The influence of deans’ transactional leadership behaviors on research productivity in public universities: The mediating effect of workplace learning capability

This study examined the effect of transactional leadership behaviors on research productivity in public universities, with organizational learning capability serving as a mediating factor. A quantitative research approach focusing on correlational design was utilized. Data were collected through a survey questionnaire administered to 519 respondents. Both measurement and structural model analyses were conducted, with deans, colleges, and individual academics serving as units of analysis. The findings revealed that deans’ contingent reward leadership behaviors significantly and positively influenced the research productivity of academics and colleges, even when controlling for workplace learning capability. Furthermore, the study demonstrated that deans’ contingent rewards and active-by-exception behaviors significantly and positively impacted workplace learning capability, accounting for 44.5% of the variance, with moderate and small effect sizes, respectively. Additionally, organizational learning capability exhibited a significant positive effect, explaining 54% of the variance in research productivity and demonstrating a moderate effect size, which indicates an unexplained variance of 46%. Bootstrapping tests confirmed that workplace learning capability partially and fully mediates the relationship between deans’ transactional leadership behaviors and research productivity. Consequently, it is imperative for college deans to enhance their contingent reward leadership behaviors and foster workplace learning capabilities to maximize their impact on research productivity.

Sequential analysis of variance: Increasing efficiency of hypothesis testing.

Researchers commonly use analysis of variance (ANOVA) to statistically test results of factorial designs. Performing an a priori power analysis is crucial to ensure that the ANOVA is sufficiently powered, however, it often poses a challenge and can result in large sample sizes, especially if the expected effect size is small. Due to the high prevalence of small effect sizes in psychology, studies are frequently underpowered as it is often economically unfeasible to gather the necessary sample size for adequate Type-II error control. Here, we present a more efficient alternative to the fixed ANOVA, the so-called sequential ANOVA that we implemented in the R package "sprtt." The sequential ANOVA is based on the sequential probability ratio test (SPRT) that uses a likelihood ratio as a test statistic and controls for long-term error rates. SPRTs gather evidence for both the null and the alternative hypothesis and conclude this process when a sufficient amount of evidence has been gathered to accept one of the two hypotheses. Through simulations, we show that the sequential ANOVA is more efficient than the fixed ANOVA and reliably controls long-term error rates. Additionally, robustness analyses revealed that the sequential and fixed ANOVAs exhibit analogous properties when their underlying assumptions are violated. Taken together, our results demonstrate that the sequential ANOVA is an efficient alternative to fixed sample designs for hypothesis testing. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Is symptom outcome the whole story?—A multilevel meta-analysis of systemic therapy for adults including family system functioning

Objective Systemic Therapy conceives mental health symptoms in the context of social systems. Previous meta-analyses on Systemic Therapy focused on symptoms. This meta-analysis aims to focus on family system functioning while including all types of outcomes. Method We conducted a systematic literature research in multiple databases (PsycInfo, PubMed, Embase, Cochrane Central). We included RCT-studies on adults with psychiatric diagnoses, which compared Systemic Therapy with active psychosocial control. The literature research resulted in 171 coded effect sizes of 32 RCTs. We conducted a random-effects three-level meta-analysis. We categorized outcomes into symptoms of patients, family system functioning, further secondary outcomes of patients, and psychopathology of family members. Results The results show a small significant overall effect size of g = .30 (CI: .15–.45, p < .001, k = 171, s = 32) for all outcomes. Systemic Therapy revealed small effect sizes with regard to family system functioning (g = .34, z = 3.51, p = .0004, k = 26, s = 12), symptoms (g = .30, z = 3.74, p = .0002, k = 73, s = 29), and further secondary outcomes (g = .32, z = 3.83, p = .0001, k = 63, s = 19). The effect sizes for psychopathology of family system members were reported rarely (k = 9, s = 6). Conclusion This meta-analysis shows the potential relevance of investigating family system functioning as a primary outcome for Systemic Therapy.

The efficacy of cognitive behavioural therapy for depression and anxiety in multiple sclerosis: A systematic review and meta-analysis

Background: Adults with multiple sclerosis (MS) frequently experience symptoms of depression and anxiety, which pose significant challenges. However, psychological support for these symptoms remains a major unmet healthcare need.Objectives: To inform the evidence base for the psychological management of adults with MS, this study examined the efficacy of cognitive behavioural therapy (CBT) interventions for improving symptoms of depression and anxiety. CBT interventions teach skills for improving the relationships between an individual's thoughts, feelings, and/or behaviours. The study also examined the role of intervention and study characteristics as moderators of treatment effects.Methods: Medline, Embase, PsycINFO, and Cochrane Central Register of Controlled Trials were searched up to August 2024 for randomised control trials.Results: A meta-analysis of 15 clinical trials (1508 participants) was conducted, which found a medium significant treatment effect size for depression symptoms (g = 0.59, 95 % Confidence Interval [CI] [0.38, 0.80]) and a small significant treatment effect size for anxiety symptoms (g = 0.38 95 % CI [0.19, 0.57]). Moderator analyses revealed treatment effects for anxiety, but not depression, were significantly larger for studies conducted in non-Western countries compared to Western countries, and for those with smaller sample sizes.Conclusions: CBT-based interventions appear efficacious for the management of depression and anxiety symptoms in adults with MS. However, future clinical trials with larger samples and more rigorous methodology are warranted. Further examination of intervention characteristics, including ways in which CBT is tailored and how this relates to outcomes, may help to refine interventions for people with MS.

Effects of web-based interventions on quality of life among patients with breast cancer: A systematic review and meta-analysis of randomized controlled trials.

Patients with breast cancer experience decreased quality of life due to various physical and psychological challenges. Web-based interventions are accessible, cost-effective, and convenient for improving their quality of life. This study evaluated whether web-based interventions improve quality of life and included only randomized controlled trials (RCTs) with clear evidence. PubMed, Embase, Cochrane Library, CINAHL, Web of Science, and PsycINFO were searched for articles published until October 16, 2023. Inclusion criteria were RCTs evaluating the effect of web-based interventions on quality of life in patients with breast cancer. The risk of bias was assessed with Cochrane's Risk of Bias Tool 2.0. Standardized mean differences were calculated with a random effects model using R version 4.0.3, and subgroup and moderator analyses were performed. Since quality of life was measured using two different instruments in two studies, 21 comparisons were analyzed from 19 RCTs. As a result, the findings suggest that web-based interventions have a small effect size on improving the quality of life for patients with breast cancer (SMD = 0.27, 95% confidence intervals [CIs]: 0.15-0.38, p = 0.03). Heterogeneity was found to be low (I2 = 40%). The quality-of-life subdomain results showed a moderate effect size on the physical functioning and a small effect size on the cognitive and emotional functioning of patients with breast cancer but no significant impact on their role or social functioning. Web-based interventions are effective in improving patients' quality of life with breast cancer; they also improve physical, cognitive, and emotional functioning. However, evidence regarding intervention methods remains inconclusive due to the limited number of RCTs, necessitating further research.

Efficacy and safety of riluzole for treating motor function in rare dyskinesia syndromes: a systematic review with meta-analysis.

We conducted a systematic review and meta-analysis to evaluate the clinical effectiveness and safety of riluzole to treat neurodegenerative dyskinesia in patients, using the Cochrane collaboration guidelines. We searched databases including Medline, Embase, and Cochrane without any language filters. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used as a guideline, and the study protocol was registered in PROSPERO (CRD42022354627). Eleven studies involving 1376 patients were included. There was a significant overall effect of riluzole on changes in motor function scores. However, the level of heterogeneity was I2 = 74%. In the subgroup analyses, there were no significant effects of riluzole on motor scores in hereditary ataxia, Parkinson's disease, or Huntington's disease. In the sensitivity analysis, there were no significant effects of riluzole on motor function scores. Furthermore, there were no significant differences in adverse events between the riluzole and placebo groups. Although riluzole may not have significant efficacy for improving motor function in neurodegenerative dyskinesia syndromes compared with placebo, it seems to have an acceptable safety profile. Moreover, it may be effective for hereditary ataxia syndromes, although there was a relatively small effect size and limited quality of evidence.

Abstract 45: Deletion of a 4-bp noncoding genomic segment orthologous to human rs1882961 results in sex-divergent changes in salt-induced hypertension in Dahl salt-sensitive rats

Most single nucleotide polymorphisms (SNPs) associated with human blood pressure (BP) are in noncoding regions of the genome and have small effect sizes in the general population. Functional studies in a controlled model system are essential to ascertain the effect of these noncoding loci on blood pressure. Such direct testing is challenging and largely absent, contributing to a critical gap between genetic discoveries and physiological understanding. We reasoned that physiological studies in genetically engineered and phenotypically permissive animal models would help to address this critical gap. We tested the hypothesis by studying the noncoding SNP rs1882961. The T allele of rs1882961, which has a frequency of approximately 30% in the European population, is associated with 0.23 mmHg higher systolic blood pressure in humans. We mapped the human rs1882961 SNP to the rat genome and used CRISPR/Cas9 to delete a 4-bp segment encompassed the rs1882961 orthologous site in the genome of the Dahl salt-sensitive (SS) rat (SS-Δrs1882961). Male SS-Δrs1882961 -/- rats exhibited significantly higher mean arterial pressure (MAP) and systolic and diastolic blood pressures (SBP and DBP) than wild-type littermates after the rats were fed a high-salt (4% NaCl) diet for 14 days (156.6 ± 5.9 vs 149.3 ± 5.1 mmHg for MAP, 179.4 ± 7.8 vs 171.9 ± 6.0 mmHg for SBP, and 133.2 ± 4.6 vs 125.1 ± 4.5 mmHg for DBP; n=7 for SS-Δrs1882961 -/- and 9 for wild-type, p&lt;0.05). In contrast, MAP, SBP, DBP, and pulse pressure of female SS-Δrs1882961 -/- rats were significantly lower than wild-type littermates on a high-salt diet (139.8 ± 1.8 vs 149.5 ± 4.7 mmHg for MAP, 159.3 ± 2.5 vs 172.3 ± 6.0 mmHg for SBP, 116.8 ± 1.5 vs 124.5 ± 3.7 mmHg for DBP, and 42.5 ± 1.6 vs 47.7 ± 2.3 mmHg for pulse pressure; n=8 for SS-Δrs1882961 -/- and 7 for wild-type, p&lt;0.05). The difference in systolic blood pressure reached more than 10 mmHg in female rats. Urinary albumin and protein levels of SS-Δrs1882961 -/- rats after 14 days on a high-salt diet tended to be higher in male and lower in female compared with wild-type littermates. The remarkable effects on BP as well as the sex-divergent changes resulted from a 4-bp noncoding segment deletion around rs1882961 orthologous site indicate that noncoding genomic segment may have profound impact on phenotypes on permissive genomic background and with informative stressors.

Psychiatric Neuroimaging at a Crossroads: Insights from Psychiatric Genetics

Thanks to methodological advances, large-scale data collections, and longitudinal designs, psychiatric neuroimaging is well-equipped to identify the neurobiological underpinnings of youth mental health problems. However, the complexity of such endeavors has become increasingly evident, as the field has been confronted by limited clinical relevance, inconsistent results, and small effect sizes. Some of these challenges parallel those historically encountered by psychiatric genetics. In past genetic research, robust findings were historically undermined by oversimplified biological hypotheses, mistaken assumptions about expectable effect sizes, replication problems, confounding by population structure, and shared biological patterns across disorders. Overcoming these challenges has contributed to current successes in the field. Drawing parallels across psychiatric genetics and neuroimaging, we identify key shared challenges as well as pinpoint relevant insights that could be gained in psychiatric neuroimaging from the transition that occurred from the candidate gene to (post) genome-wide “eras” of psychiatric genetics. Finally, we discuss the prominent developmental component of psychiatric neuroimaging and how that might be informed by epidemiological and other omics approaches. The evolution of psychiatric genetic research offers valuable lessons that may expedite the resolution of key challenges in psychiatric neuroimaging, thus potentially moving our understanding of psychiatric pathophysiology forward.

Optimizing the Diagnosis of Microcytic Hypochromic Anemia: A Comparative Evaluation of Erythrocyte and Reticulocyte Parameters.

Background Anemia is a widespread, worldwide hematological disorder, with iron deficiency anemia (IDA) and thalassemia trait (TT) being two frequently encountered forms. For effective management, it is vital to distinguish between these two conditions. Existing diagnostic methods have some limitations due to their inaccessibility and high cost. This study aims to evaluate novel hematological indices for distinguishing IDA from TT, offering potential improvements in diagnostic accuracy and patient care. Objective To compare the efficacy of novel hematological indices in differentiating IDA from TT, and to assess their sensitivity and specificity in clinical practice. Methods This cross-sectional observational study included 80 anemia patients (40 diagnosed cases of IDA and 40 of TT each). Hematological parameters were measured using the Sysmex XN-1000 analyzer (Sysmex Corporation, Kobe, Japan), and statistical analysis was conducted using the Mann-Whitney test, Pearson correlation coefficient (r), and correlation matrix. Results Significant differences were observed between IDA and TT patients in the indices studied. The Green and King Index demonstrated high diagnostic accuracy, with a sensitivity of 90% and specificity of 82%. The red cell distribution width (RDW) Index exhibited similar diagnostic performance, with a sensitivity of 90% and specificity of 77%. The England and Fraser Index showed a sensitivity of 85% and specificity of 80%, with a large effect size (r = -0.60). The correlation matrix revealed strong associations between key parameters, including a negative correlation between hemoglobin and RDWIndex (r = -0.61) and a positive correlation between mean corpuscular volume (MCV) and Shine and Lal Index (r = 0.82). On the other hand, our study found that indices like Shine and Lal and Srivastava had limited diagnostic value, with smaller effect sizes (r = 0.28 and r = -0.005, respectively). Conclusion Hematological indices, such as the Green and King, RDW, and England and Fraser indices, show strong potential for differentiating IDA from TT, with high sensitivity, specificity, and large effect sizes. The correlation matrix further supports the diagnostic utility of these indices. These tools can enhance diagnostic precision in resource-limited settings and improve patient outcomes.

An estimate of fitness reduction from mutation accumulation in a mammal allows assessment of the consequences of relaxed selection.

Each generation, spontaneous mutations introduce heritable changes that tend to reduce fitness in populations of highly adapted living organisms. This erosion of fitness is countered by natural selection, which keeps deleterious mutations at low frequencies and ultimately removes most of them from the population. The classical way of studying the impact of spontaneous mutations is via mutation accumulation (MA) experiments, where lines of small effective population size are bred for many generations in conditions where natural selection is largely removed. Such experiments in microbes, invertebrates, and plants have generally demonstrated that fitness decays as a result of MA. However, the phenotypic consequences of MA in vertebrates are largely unknown, because no replicated MA experiment has previously been carried out. This gap in our knowledge is relevant for human populations, where societal changes have reduced the strength of natural selection, potentially allowing deleterious mutations to accumulate. Here, we study the impact of spontaneous MA on the mean and genetic variation for quantitative and fitness-related traits in the house mouse using the MA experimental design, with a cryopreserved control to account for environmental influences. We show that variation for morphological and life history traits accumulates at a sufficiently high rate to maintain genetic variation and selection response. Weight and tail length measures decrease significantly between 0.04% and 0.3% per generation with narrow confidence intervals. Fitness proxy measures (litter size and surviving offspring) decrease on average by about 0.2% per generation, but with confidence intervals overlapping zero. When extrapolated to humans, our results imply that the rate of fitness loss should not be of concern in the foreseeable future.

Exploring the Role of Attachment and Coping Strategies in Sexual Orientation Disparities in Depressive Symptoms

ABSTRACT We tested whether sexual orientation disparities in depressive symptoms are partially explained by a path through attachment anxiety or avoidance leading to ineffective coping strategies. A convenience sample of 1290 individuals from two reliable data collection platforms (Credamo and Wenjuanxing) in China were included. Structural equation modeling was performed, with sexual orientation treated as the independent variable, ineffective coping strategies, attachment avoidance and anxiety as mediators, and depressive symptoms as the dependent variable. We found that lesbian, gay and bisexual (LGB) individuals reported higher levels of attachment anxiety and avoidance than heterosexual individuals, regardless of sex, with Cohen’s ds ranging from 0.25 to 0.76. For both sexes, LGB individuals reported more depressive symptoms than heterosexual individuals, with total effects (standardized regression coefficients) ranging from 0.22 to 0.26. More depressive symptoms reported by LGB individuals compared to heterosexual individuals were partially explained by a path involving attachment avoidance or anxiety leading to ineffective coping strategies, with indirect effects ranging from 0.04 to 0.09 (small effect sizes). Overall, our results suggest that psychological factors, such as the cognitive or emotional representations of self and others, as well as ineffective coping strategies, may partially explain sexual orientation disparities in depressive symptoms.

Replicability and generalizability in population psychiatric neuroimaging.

Studies linking mental health with brain function in cross-sectional population-based association studies have historically relied on small, underpowered samples. Given the small effect sizes typical of such brain-wide associations, studies require samples into the thousands to achieve the statistical power necessary for replicability. Here, we detail how small sample sizes have hampered replicability and provide sample size targets given established association strength benchmarks. Critically, while replicability will improve with larger samples, it is not guaranteed that observed effects will meaningfully apply to target populations of interest (i.e., be generalizable). We discuss important considerations related to generalizability in psychiatric neuroimaging and provide an example of generalizability failure due to "shortcut learning" in brain-based predictions of mental health phenotypes. Shortcut learning is a phenomenon whereby machine learning models learn an association between the brain and an unmeasured construct (the shortcut), rather than the intended target of mental health. Given the complex nature of brain-behavior interactions, the future of epidemiological approaches to brain-based studies of mental health will require large, diverse samples with comprehensive assessment.

Association between pathogenic beliefs and personality disorders

Background and objectivesPersonality disorders are significant entities in the field of psychiatry and serve as predisposing factors for Axis I clinical disorder. The Treatment of choice is psychotherapy, and one specific approach is Control Mastery Therapy, which emphasizes addressing Pathogenic beliefs (PB). This study aimed to investigate whether there is a relationship between PB and specific personality disorders and whether these beliefs align with the core features specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM) for that personality disorder. Materials and methodsThis study employed a retrospective cross-sectional design and included 319 participants, comprising individuals receiving treatment at the Psychotherapy Clinic at Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University between 2007 and 2023. All participants were assessed and completed the Structured Clinical Interview for DSM-IV Axis II - Personality Disorders Questionnaire (SCID-II-PQ), Pathogenic Beliefs Scale, and Outcome-Inventory (depression). A generalized linear model (binary logistic regression) was employed, and the predictors included personality disorders. The outcome was the pathogenic belief, and covariates encompassed age, sex, education, clinical diagnosis, and depression score. A sensitivity analysis was conducted to examine the effect on the model when outliers of depressive scores were present. ResultsAfter adjusting for depression, ten personality disorders were found to predict 16 pathogenic beliefs out of the 27 outcomes examined. Notably, histrionic and obsessive-compulsive personality disorders showed no association with specific pathogenic beliefs. Furthermore, certain pathogenic beliefs were predicted by multiple personality disorders, while conversely, some personality disorders were associated with multiple pathogenic beliefs as well. Sensitivity analysis revealed that outliers influenced the relationships between certain disorders and pathogenic beliefs, particularly those with small effect sizes. ConclusionsThe profound impact of pathogenic beliefs intertwined with personality disorders, particularly influenced by childhood trauma and evident in Cluster B and schizotypal disorders, underscores the critical need for targeted psychotherapeutic interventions. Addressing these beliefs directly is key to enhancing treatment efficacy and patient outcomes. Pathogenic belief should be elicited in clinical settings regardless of personality disorder, especially those who experienced depression. Moving forward, rigorous research is imperative to validate and refine therapeutic approaches aimed at reshaping pathogenic beliefs, ensuring they become pivotal in transforming clinical practice and advancing mental health care.