Investigating Moderation Effects at the Within-Person Level Using Intensive Longitudinal Data: A Two-Level Dynamic Structural Equation Modelling Approach in Mplus.

Recent technological advances have provided new opportunities for the collection of intensive longitudinal data. Using methods such as dynamic structural equation modeling, these data can provide new insights into moment-to-moment dynamics of psychological and behavioral processes. In intensive longitudinal data (t > 20), researchers often have theories that imply that factors that change from moment to moment within individuals act as moderators. For instance, a person's level of sleep deprivation may affect how much an external stressor affects mood. Here, we describe how researchers can implement, test, and interpret dynamically changing within-person moderation effects using two-level dynamic structural equation modeling as implemented in the structural equation modeling software Mplus. We illustrate the analysis of within-person moderation effects using an empirical example investigating whether changes in spending time online using social media affect the moment-to-moment effect of loneliness on depressive symptoms, and highlight avenues for future methodological development. We provide annotated Mplus code, enabling researchers to better isolate, estimate, and interpret the complexities of within-person interaction effects.

Maternal metabolic syndrome in pregnancy and child development at age 5: exploring mediating mechanisms using cord blood markers.

BACKGROUND: There is limited evidence on how the classification of maternal metabolic syndrome during pregnancy affects children's developmental outcomes and the possible mediators of this association. This study uses a cohort sample of 12,644 to 13,832 mother-child pairs from the UK Born in Bradford Study to examine the associations between maternal metabolic syndrome classification (MetS) and child development outcomes at age 5, using cord blood markers as candidate mediators. METHODS: Maternal cardiometabolic markers included diabetes, obesity, triglycerides, high-density lipoprotein cholesterol, blood pressure, hypertension, and fasting glucose during pregnancy. Cord blood markers of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, leptin, and adiponectin were used as child mediators. Child outcomes included two starting school variables: British Picture Vocabulary Scale (BPVS) and the Letter Identification Assessment (LID), and five developmental milestone domains from a national UK framework: (1) communication and language (COM); (2) personal, social, and emotional (PSE); (3) physical development (PHY); (4) literacy (LIT); and (5) mathematics (MAT). Mediation models were used to examine the associations between the classification of maternal metabolic syndrome and child developmental milestones. Models were adjusted for potential maternal, socioeconomic, and child confounders such as maternal education, deprivation, and gestational age. RESULTS: In mediation models, significant total effects were found for MetS associations with children's development in the LIT domain at age 5. MetS predicted individual cord blood mediators of lower HDL and increased leptin levels in both adjusted and unadjusted models. Total indirect effects (effects of all mediators combined) for MetS on a child's COM and PSE domain were significant, through all child cord blood mediators of LDL, HDL, triglycerides, adiponectin, and leptin for adjusted models. CONCLUSIONS: The results support the hypothesis that maternal metabolic syndrome classification during pregnancy is associated with some child developmental outcomes at age 5. After adjusting for maternal, child, and environmental covariates, maternal metabolic syndrome classification during pregnancy was associated with children's LIT domain through direct effects of maternal metabolic health and indirect effects of cord blood markers (total effects), and COM and PSE domains via changes only in a child's cord blood markers (total indirect effects).

Social expectations as a possible mechanism for adult personality change: Limited empirical evidence for the social investment principle.

OBJECTIVE: Personality traits change in both mean levels and variance across the life span but the mechanisms underlying these developmental trends remain unclear. Social Investment Principle (SIP) suggests that social expectations drive personality changes in adulthood. Accordingly, we tested whether differences between personality traits in social expectations for them can explain their different change trajectories in young adulthood. METHODS: A pool of 257 personality items was used to measure personality traits' means and variances (N = 1096), and levels expected by friends, partners and bosses/supervisors (N = 121). RESULTS: Raters were consistent in their expectations for how young adults should think, feel and behave. Traits under stronger expectations had higher mean levels and lower variances than traits under lower expectations; trait means and variances increased with age, but inconsistently with the SIP, these increases were unrelated to the traits' expected levels. CONCLUSION: Our results are only partially consistent with the SIP.

Social expectations and abilities to meet them as possible mechanisms of youth personality development.

OBJECTIVE: Personality traits change from childhood through late-adolescence, however the effects of social expectations and self-regulatory efforts remain unknown. This study aims to explore mechanisms underlying personality development by assessing mean levels personality traits from childhood to late-adolescence. METHOD: We used Common-Language California Child Q-Set to measure youths' (N = 11,000) mean personality trait levels; social expectations for these traits as perceived by parents (N = 47), teachers (N = 42) and students (N = 120); and self-regulatory efforts required for achieving the desired levels in these traits as perceived by parents (N = 27), teachers (N = 26), and students (N = 54). RESULTS: Expectations for youths' traits were consistent, regardless of raters' or youths' age. In our unique between-trait study design, traits' mean levels were positively associated with expectations for them, but age differences minimally tracked these expectations. Traits' required self-regulatory efforts were not associated with their developmental trends. CONCLUSIONS: Results were only partially consistent with existing developmental theories of personality development.

Within-family relations of mental health problems across childhood and adolescence.

BACKGROUND: While transactional models suggest that parent and child mental health reciprocally influence one another over development, research has largely focused on parent-to-child effects. Additionally, it is not known whether observed associations hold when appropriate statistical tools are used to operationalise within-family dynamics. METHODS: We investigated within-family mental health dynamics using autoregressive latent trajectory models with structured residuals, stratified by child gender. Parental psychological distress was assessed using the Kessler (K6) scale, and children's internalising and externalising problems were assessed using the Strengths and Difficulties Questionnaire. Both measures were administered at the age 3, 5, 7, 11, 14 and 17 waves of the Millennium Cohort Study (N = 10,746, ~50% female). RESULTS: Maternal psychological distress was positively associated with subsequent internalising and externalising problems for girls but only with internalising problems for boys. Paternal psychological distress was associated with boys' later internalising and externalising problems during early adolescence. Among boys, internalising problems were associated with later maternal psychological distress, while externalising problems were associated with later paternal psychological distress. Among girls, internalising problems were associated with subsequent paternal psychological distress, while externalising problems were associated with later maternal psychological distress. Finally, maternal and paternal psychological distress showed negative bidirectional associations in early childhood but positive associations in middle childhood and early adolescence. CONCLUSIONS: Findings support a transactional model of family mental health, with both child-to-parent and parent-to-child effects playing a role in the development of mental health difficulties. Mental health intervention efforts should, therefore, target the whole family system.

Does emotion dysregulation mediate the association between ADHD symptoms and internalizing problems? A longitudinal within-person analysis in a large population-representative study.

BACKGROUND: Previous research has suggested that children with attention-deficit/hyperactivity disorder (ADHD) symptoms commonly show emotion dysregulation difficulties. These difficulties may partly explain the strong tendency for internalizing problems such as anxiety and depression to co-occur with ADHD symptoms. However, no study has yet provided a longitudinal analysis of the within-person links between ADHD symptoms, emotion dysregulation, and internalizing problems necessary to examine this hypothesis from a developmental perspective. METHODS: We used data from the age 3, 5, and 7 waves of the large UK population-representative Millennium Cohort Study (n = 9,619, 4,885 males) and fit gender-stratified autoregressive latent trajectory models with structured residuals (ALT-SR) to disaggregate within- and between-person relations between ADHD symptom, emotion dysregulation, and internalizing problem symptoms. RESULTS: We found that emotion dysregulation significantly mediated the longitudinal within-person association between ADHD symptoms and internalizing problems. CONCLUSIONS: Results underline the promise of targeting emotion dysregulation as a means of preventing internalizing problems co-occurring with ADHD symptoms.

A symptom level perspective on reactive and proactive aggressive behaviours and ADHD symptoms in childhood.

OBJECTIVE: Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most prevalent childhood disorders, affecting around 3.4% of children worldwide. A common and impairing correlate of ADHD is aggressive behaviour. ADHD symptoms and aggression are both heterogeneous and it has been speculated that certain symptoms of ADHD might be more important in aggressive behaviours of different types than others. This study uses a symptom-level analysis to investigate the concurrent and temporal links between ADHD symptoms and aggressive behaviours. METHODS: Using Gaussian Graphical Models and Graphical Vector Autoregression Models, longitudinal and cross-sectional networks of ADHD symptoms and aggressive behaviours, measured using parent-reported Social Behaviour Questionnaires, were estimated. Participants included 1,246 children taking part in the longitudinal Swiss z-proso cohort study at ages 7, 9 and 11. RESULTS: The longitudinal network highlighted that ADHD symptoms and aggressive behaviours share a multitude of reciprocal temporal relations, with inattentive ADHD symptoms preceding both reactive and proactive aggression. Cross-sectional networks suggested that hyperactive/impulsive symptoms were predominantly connected to reactive aggressive behaviours but also to a form of proactive aggression, namely dominating other children. CONCLUSION: Findings provide preliminary evidence which specific symptoms are the most promising targets for reducing aggressive behaviours in children with ADHD. They also highlight the potential importance of targeting feedback loops resulting from aggressive behaviours. Future research is needed to better understand the mechanisms through which ADHD and aggressive behaviours become linked.

Polygenic risks for joint developmental trajectories of internalizing and externalizing problems: findings from the ALSPAC cohort.

BACKGROUND: Joint developmental trajectories of internalizing and externalizing problems show considerable heterogeneity; however, this can be parsed into a small number of meaningful subgroups. Doing so offered insights into risk factors that lead to different patterns of internalizing/externalizing trajectories. However, despite both domains of problems showing strong heritability, no study has yet considered genetic risks as predictors of joint internalizing/externalizing problem trajectories. METHODS: Using parallel process latent class growth analysis, we estimated joint developmental trajectories of internalizing and externalizing difficulties assessed across ages 4 to 16 using the Strengths and Difficulties Questionnaire. Multinomial logistic regression was used to evaluate a range of demographic, perinatal, maternal mental health, and child and maternal polygenic predictors of group membership. Participants included 11,049 children taking part in the Avon Longitudinal Study of Parents and Children. Polygenic data were available for 7,127 children and 6,836 mothers. RESULTS: A 5-class model was judged optimal: Unaffected, Moderate Externalizing Symptoms, High Externalizing Symptoms, Moderate Internalizing and Externalizing Symptoms and High Internalizing and Externalizing Symptoms. Male sex, lower maternal age, maternal mental health problems, maternal smoking during pregnancy, higher child polygenic risk scores for ADHD and lower polygenic scores for IQ distinguished affected classes from the unaffected class. CONCLUSIONS: While affected classes could be relatively well separated from the unaffected class, phenotypic and polygenic predictors were limited in their ability to distinguish between different affected classes. Results thus add to existing evidence that internalizing and externalizing problems have mostly shared risk factors.

The role of harsh parenting practices in early- to middle-childhood socioemotional development: An examination in the Millennium Cohort Study.

Patterson's coercion model describes a gradual escalation in maladaptive parent-child transactions whereby externalizing behaviors lead to increases in maladaptive parenting and vice versa. The current study investigates the role of (predominantly mother-reported) harsh parenting practices in the within-person development of conduct problems, hyperactive/inattentive behaviors, and emotional problems. A random-intercept cross-lagged panel model was fit across ages 3, 5, and 7 (N = 14,037, 49% female, 84% White) using the UK population-representative Millennium Cohort Study. Findings support Patterson's coercion model, providing evidence for reciprocal within-family relations between parenting practices and child behaviors. They suggest the importance of addressing parenting difficulties in families where children present with socioemotional difficulties in order to help prevent the accumulation of additional issues.

Patterns of adverse childhood experiences and associations with prenatal substance use and poor infant outcomes in a multi-country cohort of mothers: a latent class analysis.

BACKGROUND: This paper enumerates and characterizes latent classes of adverse childhood experiences and investigates how they relate to prenatal substance use (i.e., smoking, alcohol, and other drugs) and poor infant outcomes (i.e., infant prematurity and low birthweight) across eight low- and middle-income countries (LMICs). METHODS: A total of 1189 mother-infant dyads from the Evidence for Better Lives Study cohort were recruited. Latent class analysis using the Bolck, Croon, and Hagenaars (BCH) 3-step method with auxiliary multilevel logistic regressions was performed. RESULTS: Three high-risk classes and one low-risk class emerged: (1) highly maltreated (7%, n = 89), (2) emotionally and physically abused with intra-familial violence exposure (13%, n = 152), (3), emotionally abused (40%, n = 474), and (4) low household dysfunction and abuse (40%, n = 474). Pairwise comparisons between classes indicate higher probabilities of prenatal drug use in the highly maltreated and emotionally abused classes compared with the low household dysfunction and abuse class. Additionally, the emotionally and physically abused with intra-familial violence exposure class had higher probability of low birthweight than the three remaining classes. CONCLUSION: Our results highlight the multifaceted nature of ACEs and underline the potential importance of exposure to childhood adversities on behaviors and outcomes in the perinatal period. This can inform the design of antenatal support to better address these challenges.

Developmental trajectories of ADHD symptoms in a large population-representative longitudinal study.

BACKGROUND: Previous research has suggested that there is substantial heterogeneity in the developmental trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms. Sometimes, qualitative distinctions between trajectories with different ages of onset and/or patterns of remission are made; however, little is known about the predictors and broader clinical meaningfulness of these candidate 'developmental subtypes' of ADHD symptoms. METHODS: We applied latent class growth analysis to data from the UK Millennium Cohort Study (MCS; N = 11 316; ages 3, 5, 7, 11 and 14) to evaluate whether developmental trajectories of ADHD symptoms differing in early life predictors could be identified. Our optimal model included six trajectory groups, labelled unaffected (34.9% of the sample), mildly affected (24.1%), subclinical remitting (12.8%), pre-school onset partially remitting (14.1%), developmentally increasing (7.6%) and pre-school onset persistent (6.4%). RESULTS: Factors such as gender, conduct problems, cognitive ability, maternal education, premature birth, peer problems and school readiness scores differentiated between specific ADHD symptom trajectories. CONCLUSIONS: Taken together, our findings provide preliminary evidence that distinguishing different trajectories of ADHD symptoms could be clinically informative.

Teacher Versus Parent Informant Measurement Invariance of the Strengths and Difficulties Questionnaire.

BACKGROUND AND OBJECTIVES: Obtaining a multi-informant perspective is important when assessing mental health issues in childhood and adolescence. Obtaining ratings from both parents and teachers also facilitates the evaluation of similarities and contrasts in the nature and severity of symptoms across home and school contexts. However, these informants may differ in their interpretations of observed behaviors, raising questions about the validity of comparing parents' and teachers' ratings. METHODS: We evaluated the cross-informant measurement invariance of one of the most widely used measures of child and adolescent mental health: The Strengths and Difficulties Questionnaire (SDQ). Using data from the UK-population representative Millennium Cohort Study, we evaluated configural, metric, and scalar measurement invariance across parents and teachers when children were aged 7 (N = 10,221) and 11 (N = 10,543). RESULTS: Scalar measurement invariance held at both ages. Parents reported higher levels of symptoms in all domains measured at both ages as well as higher prosociality. CONCLUSIONS: For a UK sample, valid comparisons of parent and teacher SDQ ratings at ages 7 and 11 appear to be possible, facilitating the evaluation of contextual differences in child mental health problems. Further, parents report more problem and prosocial behavior in their children than teachers attribute to them.

Links between perinatal risk factors and maternal psychological distress: A network analysis.

INTRODUCTION: This paper explores a range of perinatal risk factors that may increase maternal vulnerability to postnatal psychological distress in a sample of 17 531 women participating in the Millennium Cohort Study, a diverse British, longitudinal birth cohort study. MATERIAL AND METHODS: Using a graphical network modeling framework, this study models the links between postnatal psychological distress and perinatal risk factors, while controlling for sociodemographic factors and history of depression and anxiety. Postnatal psychological distress was assessed at 9 months postpartum using the Rutter Malaise Inventory. RESULTS: Results of the graphical network models indicate that lower levels of happiness about the pregnancy (Edge weight [w] = 0.084, 95% CI = 0.069-0.100, b = 0.095), smoking during pregnancy (w = 0.026, 95% CI = -0.009-0.060, b = 0.029), infection during pregnancy (w = 0.071, 95% CI = 0.024-0.118, b = 0.090), hyperemesis gravidarum (w = 0.068, 95% CI = 0.013-0.123, b = 0.083), baby in special care (w = 0.048, 95% CI = -0.004-0.099, b = 0.062), not being white (w = 0.101, 95% CI = 0.062-0.140, b = 0.118), being from a more deprived area (w = -0.028, 95% CI = -0.051 to -0.005, b = -0.039), lower income (w = -0.025, 95% CI = -0.055-0.005, b = -0.036), and history of depression or anxiety (w = 0.574, 95% CI = 0.545-0.603, b = 0.764) were associated with increased psychological distress. CONCLUSIONS: Some perinatal risk factors may be directly associated with postnatal psychological distress, but many risk factors appear to be primarily associated with demographic factors. This emphasizes the importance of taking a holistic approach when evaluating an individual's risk of developing postnatal psychological distress.

Prenatal maternal infections and children's socioemotional development: findings from the UK Millennium Cohort Study.

Previous research suggests that prenatal maternal infections may be associated with increased odds of children having a neurodevelopmental disorder. However, little evidence exists on associations with broader child outcomes, especially subclinical symptoms. Participants were the N = 14,021 members of the population-representative UK Millennium Cohort Study. We examined associations between prenatal maternal infections, both maternal-reported and hospital-recorded, and children's socioemotional development, using the Strengths and Difficulties Questionnaire (SDQ) at age three. Maternal-reported prenatal infections were associated with increased emotional symptoms, after adjusting for several potential confounds and covariates. Hospital-recorded prenatal infections were not associated with children's socioemotional outcomes, after adjusting for potential confounding and covarying factors. Findings suggest that prenatal maternal infections, particularly those which the mothers remember months later, may be associated with increased emotional problems in early childhood. This emphasises the need for screening for and preventing infections during pregnancy. Further, the occurrence of prenatal infection indicates the potential need for early intervention for children's emotional difficulties.

Daily life affective dynamics as transdiagnostic predictors of mental health symptoms: An ecological momentary assessment study.

BACKGROUND: Affective dynamics have been identified as a correlate of a broad span of mental health issues, making them key candidate transdiagnostic factors. However, there remains a lack of knowledge about which aspects of affective dynamics - especially as they manifest in the course of daily life - relate to a general risk for mental health issues versus specific symptoms. METHODS: We leverage an ecological momentary assessment (EMA) study design with four measures per day over a two-week period to explore how negative affect levels, inertia, lability, and reactivity to provocation and stress in the course of daily life relate to mental health symptoms in young adults (n = 256) in the domains of anxiety, depression, psychosis-like symptoms, behaviour problems, suicidality, and substance use. RESULTS: Dynamic structural equation modelling (DSEM) suggested that negative affect levels in daily life were associated with depression, anxiety, indirect and proactive aggression, psychosis, anxiety, and self-injury; negative affective lability was associated with depression, physical aggression, reactive aggression, suicidal ideation, and ADHD symptoms; negative affective inertia was associated with depression, anxiety, physical aggression, and cannabis use; and emotional reactivity to provocation was related to physical aggression. LIMITATIONS: The cross-sectional design, the limited span of mental health issues included, and the convenience nature and small size of the sample are limitations. CONCLUSIONS: Findings suggest that a subset of mental health symptoms have shared negative affective dynamics patterns. Longitudinal research is needed to rigorously examine the directionality of the effects underlying the association between affective dynamics and mental health issues.

Longitudinal Invariance of the Strengths and Difficulties Questionnaire Across Ages 4 to 16 in the ALSPAC Sample.

The Strengths and Difficulties Questionnaire (SDQ) has been widely used to study children's psychosocial development longitudinally; however, such analyses assume longitudinal measurement invariance, that is, they presuppose that symptom manifestations are measured comparably across different ages. Violations of this assumption could bias longitudinal analyses and should therefore be empirically tested. This study tested longitudinal measurement invariance within a confirmatory factor analysis framework in the U.K.-based Avon Longitudinal Study of Parents and Children (N = 13,988). Results indicated that SDQ scores showed configural, metric, scalar, and residual invariance across ages 7, 8, 9, 11, 13, and 16, supporting its use for comparing variances, covariances, and means over time within a latent variable model as well as using observed scores. At age 4, configural invariance was not supported, indicating that mental health symptoms as measured by the SDQ manifest differently at this age, thus necessitating caution when comparing symptoms as measured by SDQ scores at this age to later ages.

Investigating general and specific psychopathology factors with nuance-level personality traits.

Mental health disorders share substantial variance, prompting researchers to develop structural models that can capture both generalised psychopathology risk and disorder/symptom-specific variation. This study investigated the associations of the general and specific psychopathology factors with multiple personality trait hierarchy levels: broad domains, their facets and nuances (N = 1839 Estonian adults). A bi-factor model with a general 'p' factor and specific factors for internalising problems, thought disorders and substance use best represented psychopathology structure. Although traits' predictive accuracy varied across psychopathology factors, nuances (the lowest level personality units) provided higher predictive accuracy and higher discriminant validity than domains. For example, traits related to high vulnerability, depression and immoderation and low friendliness and achievement striving were most strongly associated with the p factor. Nuances may prove useful for predicting and understanding general and specific psychopathology forms.

The role of moment-to-moment dynamics of perceived stress and negative affect in co-occurring ADHD and internalising symptoms.

A maladaptive response to stress in individuals with high ADHD traits may be a key factor explaining co-occurring ADHD symptoms and internalising problems. The current study investigates whether between-person differences in ADHD traits are associated with differences in the within-person moment-to-moment coupling of stress and negative affect; and whether these can explain between-person differences in internalising problems (N = 262, median-age 20). Results of a dynamic structural equation model indicated that between-person differences in ADHD traits significantly moderated the daily life coupling between stress and negative affect. Further, higher ADHD traits were associated with stronger stress carry-over and higher mean levels of negative affect. Stress carry-over and mean levels of negative affect mediated the association between ADHD traits and internalising problems.

Testing for Within × Within and Between × Within Moderation using Random Intercept Cross-Lagged Panel Models.

Random-Intercept Cross-Lagged Panel Models allow for the decomposition of measurements into between- and within-person components and have hence become popular for testing developmental hypotheses. Here, we describe how developmental researchers can implement, test and interpret interaction effects in such models using an empirical example from developmental psychopathology research. We illustrate the analysis of Within × Within and Between × Within interactions utilising data from the United Kingdom-based Millennium Cohort Study within a Bayesian Structural Equation Modelling framework. We provide annotated Mplus code, allowing users to isolate, estimate and interpret the complexities of within-person and between person dynamics as they unfold over time.

Psychometric evaluation of an adapted version of the perceived stress scale for ecological momentary assessment research.

Ecological momentary assessment (EMA) methodologies are commonly used to illuminate the predictors and impacts of experiencing subjective stress in the course of daily life. The validity of inferences from this research is contingent on the availability of measures of perceived momentary stress that can provide valid and reliable momentary stress scores. However, studies of the development and validation of such measures have been lacking. In this study, we use an EMA data collection design to examine the within- and between- person reliability and criterion validity and between-person gender measurement invariance of a brief EMA-adapted measure of a widely used trait measure of stress: the Perceived Stress Scale (PSS). Scores showed high internal consistency reliability and significant correlations with a range of criterion validity measures at both the within- and between-person level. Gender measurement invariance up to the scalar level also held for scores. Findings support the use of the EMA-adapted PSS presented in the current study for use in community-ascertained samples to address research questions relating to the influences on and effects of momentary stress and their gender differences.