Redefining effect size interpretations for psychotherapy RCTs in depression

Introduction: Effect sizes are often used to interpret the magnitude of a result and in power calculations when planning research studies. However, as effect size interpretations are context-dependent, Jacob Cohen’s suggested guidelines for what represents a small, medium, and large effect are unlikely to be suitable for a diverse range of research populations and interventions. Our objective here is to determine empirically-derived effect size thresholds associated with psychotherapy randomized controlled trials (RCTs) in depression by calculating the effect size distribution. Methods: We extracted effect sizes from 366 RCTs provided by the systematic review of Cuijpers and colleagues (2020) on psychotherapy for depressive disorders across all age groups. The 50th percentile effect size, as this represents a medium effect size, and the 25th (small) and 75th (large) percentile effect sizes were calculated to determine empirically-derived effect size thresholds. Results: After adjusting for publication bias, 0.27, 0.53, and 0.86 represent small, medium, and large effect sizes, respectively, for psychotherapy treatment for depressive disorders. Discussion: The effect size distribution for psychotherapy treatment of depression indicates that observed effect size thresholds are larger than Cohen’s suggested effect size thresholds (0.2, 0.5, and 0.8). These results have implications for the interpretation of study effects and the planning of future studies via power analyses, which often use effect size thresholds.publishedVersio

What are we measuring with the morningness–eveningness questionnaire? Exploratory factor analysis across four samples from two countries

Individual variability in diurnal preference or chronotype is commonly assessed with self-report scales such as the widely used morningness–eveningness questionnaire (MEQ). We sought to investigate the MEQ’s internal consistency by applying exploratory factor analysis (EFA) to determine the number of underlying latent factors in four different adult samples, two each from the United Kingdom and Brazil (total N = 3,457). We focused on factors that were apparent in all samples, irrespective of particular sociocultural diversity and geographical characteristics, so as to show a common core reproducible structure across samples. Results showed a three-factor solution with acceptable to good model fit indexes in all studied populations. Twelve of the 19 MEQ items in the three-correlated factor solution loaded onto the same factors across the four samples. This shows that the scale measures three distinguishable, yet correlated constructs: (1) items related to how people feel in the morning, which we termed efficiency of dissipation of sleep pressure (recovery process) (items 1, 3, 4, 5, 7, 9, 13, and 19); (2) items related to how people feel before sleep, which we called sensitivity to buildup of sleep pressure (items 2, 10, and 12); and (3) peak time of cognitive arousal (item 11). Although the third factor was not regarded as consistent since only one item was common among all samples, it might represent subjective amplitude. These results suggested that the latent constructs of the MEQ reflect dissociable homeostatic processes in addition to a less consistent propensity for cognitive arousal at different times of the day. By analyzing answers to MEQ items that compose these latent factors, it may be possible to extract further knowledge of factors that affect morningness–eveningness

Propriedades psicométricas de questionários de matutinidade-vespertinidade comumente usados em adultos e adolescentes por meio da aplicação de modelagem de equações estruturais

Introduction:morningness-eveningness refers to individual differences in sleep-wake patterns, preferred time for activities and levels of alertness in the morning and evening. It is believed to be a unidimensional construct but this has not been properly tested via robust structural equation modeling techniques. Objective: to investigate the underlying factor structure of two morningness-eveningness questionnaires that are frequently used in the international literature in adults (the MorningnessEveningness Questionnaire: MEQ) and in children and adolescents (the MorningnessEveningness Scale for Children: MESC). Methods: the MEQ’s internal consistency was investigated by conducting exploratory factor analysis in four different adult samples, two each from Brazil and the United Kingdom (total N = 3,457). Confirmatory factor analysis was applied to the MESC based on a sample of Brazilian adolescents (N=394) to investigate if the factor solution found in the MEQ could also be used to structure the confirmatory model. Results: we found a three-correlated factor solution with acceptable model fit indexes across all four studied adult populations who answered the MEQ. The domains/factors were formed by(1) questionnaire items related to how people feel in the morning (interpreted as the efficiency of dissipation of sleep pressure or a recovery process); (2) items related to how people feel before sleep (interpreted as the sensitivity to buildup of sleep pressure); and (3) peak time of cognitive arousal. In the following study, these three underlying constructs were confirmed with answers in the MESC using the sample of adolescent. We also tested a bifactor model-S-1 model in the data from the adolescents considering above mentioned factor two as the general factor because sensitivity to the buildup of sleep pressure/phase delay has been proposed tobe themost deterministic aspectsofsleep that drive latter sleep patterns in adolescence. Conclusion: the morningnesseveningness construct found in both scales and ages was found to be multidimensional. By analyzing factors that affect each factor in coming studies it may be possible both to identify people at a higher risk of sleep-related problems and to design factor-specific interventions.Introdução: matutinidade-vespertinidade refere-se às diferenças individuais nos padrões de sono-vigília, horário preferido para atividades e níveis de alerta pela manhã e à noite. Acredita-se que seja uma construção unidimensional, mas isso não foi apropriadamente testado via técnicas robustas de modelagem de equação estrutural. Objetivo: investigar a estrutura fatorial subjacente a doisquestionários de matutinidade-vespertinidade que são frequentemente utilizados na literatura internacional para a população de adultos (Morningness-Eveningness Questionnaire: MEQ) e e crianças e adolescentes (Morningness-Eveningness Scale for Children: MESC). Métodos: a consistência interna do MEQ foi investigada por meio da análise fatorial exploratória em quatro diferentes amostras de adultos, duas do Brasil e duas do Reino Unido (total N = 3.457). A análise fatorial confirmatória do MESC, advinda de uma mostra de adolescentes brasileiros (N=394), partiu dos achados da solução fatorial encontrada no MEQ para estruturar o modelo confirmatório. Resultados: encontramos uma solução de três fatores correlacionados com índices de ajuste de modelo aceitáveis em todas as quatro populações adultas estudadas que responderam ao MEQ. Os domínios/fatores foram formados por (1) itens do questionário relacionados a como as pessoas se sentem pela manhã (interpretado como a eficiência da dissipação da pressão do sono ou um processo de recuperação); (2) itens relacionados a como as pessoas se sentem antes de dormir (interpretado como a sensibilidade ao aumento da pressão do sono); e (3) tempo de pico de excitação cognitiva. No estudo seguinte, esses três construtos subjacentes foram confirmados com respostas no MESC pela amostra de adolescentes. Também testamos um modelo bifatorial-S-1 nos dados dos adolescentes, considerando o fator 2 acima citado como o fator geral, porque a sensibilidade ao acúmulo de pressão do sono/atraso da fase foi proposta como sendo os aspectos mais determinísticos do sono que impulsionam o sono posterior padrões na adolescência. Conclusão: o construto matutinidade-vespertinidade encontrado em ambas as escalas e idades mostrou-se multidimensional. Ao analisar os fatores que afetam cada fator nos próximos estudos, pode ser possível identificar pessoas com maior risco de problemas relacionados ao sono e projetar intervenções específicas de fatores.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

What are we measuring with the Morningness-Eveningness Questionnaire? Exploratory factor analysis across four samples from two countries

Individual variability in diurnal preference or chronotype is commonly assessed with selfreport scales such as the widely used Morningness-Eveningness Questionnaire (MEQ). We sought to investigate the MEQ’s internal consistency by applying exploratory factor analysis (EFA) to determine the number of underlying latent factors in four different adult samples, two each from the United Kingdom and Brazil (total N=3,457). We focused on factors that were apparent in all samples, irrespective of particular sociocultural diversity and geographical characteristics, so as to show a common core reproducible structure across samples. Results showed a three-factor solution with acceptable to good model fit indexes in all studied populations. Twelve of the 19 MEQ items in the three-correlated factor solution loaded onto the same factors across the four samples. This shows that the scale measures three distinguishable, yet correlated constructs: 1) items related to how people feel in the morning, which we termed efficiency of dissipation of sleep pressure (recovery process) (items 1, 3, 4, 5, 7, 9, 13, and 19); 2) items related to how people feel before sleep, which we called sensitivity to build-up of sleep pressure (items 2, 10, and 12); and 3) peak time of cognitive arousal (item 11). Although the third factor was not regarded as consistent since only one item was common among all samples, it might represent subjective amplitude. These results suggested that the latent constructs of the MEQ reflect dissociable homeostatic processes in addition to a less consistent propensity for cognitive arousal at different times of the day. By analysing answers to MEQ items that compose these latent factors, it may be possible to extract further knowledge of factors that affect morningness-eveningness

Fractionation of executive functions in adolescents from Iran: invariance across age and socioeconomic status

Executive functions (EFs) are cognitive skills that regulate thoughts and behavior. The seminal EF unity and diversity theoretical framework proposes the existence of three correlated EF latent domains (inhibition, updating, and switching) that become distinguishable from a certain moment during adolescence, but it is unclear how age and socioeconomic status (SES) afect these abilities. Here, we assessed 407 9-15-year-old Iranians of variable SES using an open-access battery of executive function tests that includes two tasks of each EF domain and allows for sociocultural adaptations regarding language and stimuli. Various EF model confgurations proposed in the literature were tested (one, two and three EF latent factor, nested and bifactor-S-1 models) using confrmatory factor analyses. In addition, to explore the unbiased efects of age and SES, we performed invariance testing (across age and SES) using multiple indicators multiple causes (MIMIC) model to the best ftting model solution. The three-correlated EF factor model had the best ft and was mostly invariant across age and SES, with all three EF latent traits improving with age, while SES exerted only minimal positive efects on shifting and updating. We concluded that the three separable EF domains, found in adults and adolescents of other ages from diferent populations, can already be detected from the beginning of adolescence when culturally and psychometrically appropriate EF tasks are used. Additionally, these abilities continue to improve with age and are little afected by SES, suggesting that the unity and diversity framework is useful to study the cross-country generality of EF development.publishedVersio