Revisiting longitudinal qualitative studies in social work: considerations for design and methodological insights.

This paper undertakes an analysis and discussion of the methodological challenges and insights derived from three longitudinal qualitative studies, all conducted in Chile during the COVID-19 pandemic and subject to comprehensive theoretical-methodological reflection processes centred on their respective designs. This analysis makes a significant contribution to interdisciplinary discussions within social research, with a particular emphasis on longitudinal trajectories. First, we present a comparative analysis of three studies in social work, utilising Saldaña's questions addressing changes and learning in longitudinal studies. The first study explores the labour trajectories of researchers, the second focuses on the educational trajectories of students, and the last examines therapeutic alliance trajectories between social workers and families within the child protection system. Following this, we delve into the methodological decisions made by the research group during the execution of these longitudinal studies. This encompasses an examination of participant involvement, temporal definitions of the adopted designs, and the most suitable methodological tools for analysing change processes over time. The outcomes of this comparative analysis reveal the distinctive characteristics of the three longitudinal studies, providing insights into how the time dimension is explored within them. We highlight key criteria essential for consideration in longitudinal qualitative research, particularly regarding participants and methodology. In conclusion, we advocate for an expanded reflection within the realm of longitudinal qualitative methodology, encompassing aspects such as design choices, approaches to data analysis, integration of technology in information processing, and strategies for maintaining participant engagement.

Basic moral sensitivity, moral disengagement, and defender self-efficacy as predictors of students' self-reported bystander behaviors over a school year: a growth curve analysis.

Though school children tend to view peer victimization as morally wrong most do not to intervene on the victim's behalf and some instead choose to aid the victimizer. The aim of this longitudinal study was to investigate how students' defending and pro-aggressive bystander behaviors evolved over the course of one school year and their association to basic moral sensitivity, moral disengagement, and defender self-efficacy. Three-hundred-fifty-three upper elementary school students (55% girls; 9.9-12.9 years of age) each completed self-report surveys at three points during one school year. Results from latent growth curve models showed that pro-aggressive bystander behavior remained stable over the year, whereas defending behavior decreased. Moreover, students who exhibited greater basic moral sensitivity were both less likely to be pro-aggressive and simultaneously more likely to defend. Students with defender self-efficacy were not only associated with more defending behavior at baseline but also were also less likely to decrease in defender behavior over time. Conversely, students reporting a higher degree of moral disengagement were linked to more pro-aggressive behavior, particularly when also reporting lower basic moral sensitivity. These short-term longitudinal results add important insight into the change in bystander behavior over time and how it relates to students' sense of morality. The results also highlight the practical necessity for schools to nurture students' sense of morality and prosocial behavior in their efforts to curb peer victimization.

THE USE OF CLASSIFIERS IN VIETNAMESE IN TYPICAL AND ATYPICAL LANGUAGE DEVELOPMENT.

The acquisition of numeral classifiers and their associated syntactic structures has been documented and studied in a broad range of East and Southeast Asian languages among typically-developing (TD) young speakers. However, little research has considered how classifiers are acquired by children with developmental language disorder (DLD). The current paper compares and analyzes the development of numeral classifier patterns among a set of Vietnamese speakers, TD and DLD, studied over three years, from kindergarten to second grade. The investigation highlights differences in the performance of children with TD and DLD and describes the areas of classifier use that seem to be most challenging. Children with DLD produced more errors of classifier omission in kindergarten, showed more random alternations in representational forms, and delays in the development of three element classifier structures. Findings are discussed in terms of future directions in the study of classifier use in Vietnamese speakers with DLD.

Testing for longitudinal bidirectional associations between self-compassion, self-criticism, and positive body image components.

Previous cross-sectional studies have reported associations between self-compassion, self-criticism, and positive body image, yet prospective studies establishing the temporal order of these relationships are missing. The present study sought to clarify the nature of these associations by investigating possible longitudinal bi-directional links between self-compassion, self-criticism, and three components of positive body image (body appreciation, functionality appreciation, and body image flexibility). Data were analyzed from 2982 adult women who completed survey instruments at baseline (T0), four-month follow-up (T1), and eight-month follow-up (T2). Attrition rate ranged from 0-56% across time-points. Cross-lagged panel models were computed to test for bidirectional associations. We found evidence of reciprocal, negative associations between self-criticism and the three components of positive body image across the three time-points. We also found evidence that T0 self-compassion predicted increased body image flexibility and functionality appreciation at T1 (paths were non-significant from T1 to T2), whereas T0 body appreciation predicted increased T1 self-compassion (but was non-significant from T1 to T2). Findings suggest that compassionate and uncritical ways of responding to the self may be relevant precursors and outcomes to positive body image, depending on the timing of assessment, highlighting viable targets for intervention.

Associations Between Breastfeeding, Maternal Emotional Availability, and Infant-Mother Attachment: The Role of Coparenting.

BACKGROUND: Breastfeeding is a parenting practice that combines close intimate contact with the opportunity to be sensitive and responsive to the infant, and may have direct and indirect relations with infant attachment. However, researchers have produced inconsistent findings, suggesting there may be other mechanisms involved. Coparenting may play a significant role, as it has been consistently associated with mother-infant relationships. RESEARCH AIMS: The aims of this study were to examine: (1) whether breastfeeding would be directly associated with infant-mother attachment; (2) whether this association was also indirect, through mothers' quality of caregiving; and (3) whether partners' coparenting support moderates breastfeeding's indirect association with attachment. METHODS: This was a prospective, longitudinal study that drew data from a larger NIH-funded study on sleep and family relationships (R01HD052809). Mothers reported on their feeding practices and coparenting relationships. Independent observations were used to assess mothers' emotional availability toward infants. A separate team of observers assessed infant-mother attachment. RESULTS: Exclusive breastfeeding during the first 6 months, and longer duration of any breastfeeding across the 1st year, were directly associated with more secure infant-mother attachment. These associations were also indirect, through maternal emotional availability. Coparenting was a significant moderator, such that the influence of longer breastfeeding duration on improved emotional availability, and, in turn, on more secure attachment, was significant only for mothers who perceived coparenting quality to be low. CONCLUSION: Findings highlighted the importance of breastfeeding on both the quality of mothering and infant attachment, but also emphasized that coparenting support may be particularly important for mothers who are unable to breastfeed.

Longitudinal assessment of ventricular volume trajectories in early-stage schizophrenia: evidence of both enlargement and shrinkage.

BACKGROUND: Lateral ventricular enlargement represents a canonical morphometric finding in chronic patients with schizophrenia; however, longitudinal studies elucidating complex dynamic trajectories of ventricular volume change during critical early disease stages are sparse. METHODS: We measured lateral ventricular volumes in 113 first-episode schizophrenia patients (FES) at baseline visit (11.7 months after illness onset, SD = 12.3) and 128 age- and sex-matched healthy controls (HC) using 3T MRI. MRI was then repeated in both FES and HC one year later. RESULTS: Compared to controls, ventricular enlargement was identified in 18.6% of patients with FES (14.1% annual ventricular volume (VV) increase; 95%CI: 5.4; 33.1). The ventricular expansion correlated with the severity of PANSS-negative symptoms at one-year follow-up (p = 0.0078). Nevertheless, 16.8% of FES showed an opposite pattern of statistically significant ventricular shrinkage during ≈ one-year follow-up (-9.5% annual VV decrease; 95%CI: -23.7; -2.4). There were no differences in sex, illness duration, age of onset, duration of untreated psychosis, body mass index, the incidence of Schneiderian symptoms, or cumulative antipsychotic dose among the patient groups exhibiting ventricular enlargement, shrinkage, or no change in VV. CONCLUSION: Both enlargement and ventricular shrinkage are equally present in the early stages of schizophrenia. The newly discovered early reduction of VV in a subgroup of patients emphasizes the need for further research to understand its mechanisms.

Longitudinal MRI of the developing ferret brain reveals regional variations in timing and rate of growth.

Normative ferret brain development was characterized using magnetic resonance imaging. Brain growth was longitudinally monitored in 10 ferrets (equal numbers of males and females) from postnatal day 8 (P8) through P38 in 6-d increments. Template T2-weighted images were constructed at each age, and these were manually segmented into 12 to 14 brain regions. A logistic growth model was used to fit data from whole brain volumes and 8 of the individual regions in both males and females. More protracted growth was found in males, which results in larger brains; however, sex differences were not apparent when results were corrected for body weight. Additionally, surface models of the developing cortical plate were registered to one another using the anatomically-constrained Multimodal Surface Matching algorithm. This, in turn, enabled local logistic growth parameters to be mapped across the cortical surface. A close similarity was observed between surface area expansion timing and previous reports of the transverse neurogenic gradient in ferrets. Regional variation in the extent of surface area expansion and the maximum expansion rate was also revealed. This characterization of normative brain growth over the period of cerebral cortex folding may serve as a reference for ferret studies of brain development.

Mixed models for repetitive measurements: the basics.

Linear mixed models are regularly used within the field of reproductive medicine. This manuscript explains the basics of mixed models, when they could be used, and how they could be applied.

Social participation, loneliness, and physical inactivity over time: evidence from SHARE.

OBJECTIVES: We aimed to explore the reciprocal effects of social participation, loneliness, and physical inactivity over a period of 6 years in a representative sample of European adults over 50 years old. DESIGN: A longitudinal study with a six-year follow-up period was conducted. SETTING: Four waves of the Survey of Health, Ageing and Retirement in Europe project were used. PARTICIPANTS: This study includes 64,887 participants from Europe and Israel, who were aged 50 or older at the first time. MEASUREMENTS: The relationship between participation in social activities, loneliness and physical inactivity was analyzed, controlling for age, gender, and disability. A series of cross-lagged panel models (CLPMs) were applied to analyze the relationships among these variables. RESULTS: A CLPM with equal autoregressive cross-lagged effects across waves was the best fit to the data (χ2 = 7137.8, CFI = .972, RMSEA = .049, SRMR = .036). The autoregressive effects for the three variables showed high stability across waves, and all the cross-lagged effects in the model were statistically significant. Social activity and physical inactivity maintained a strong negative cross-lagged effect, while their cross-lagged effects on loneliness were comparatively smaller. Social activity had a positive cross-lagged effect on loneliness, while physical inactivity had a negative cross-lagged effect on loneliness. CONCLUSIONS: These findings highlight the importance of promoting physical activity and social participation and addressing loneliness through targeted interventions in older adults.

Keeping you connected or keeping you addicted? Weekly use of social media platforms is associated with hazardous alcohol use and problem gambling among adults.

AIMS: A wide variety of social media platforms exist, each offering tailored solutions to attract specific target audiences based on their social media needs and interests. This diversity may pose a risk factor for the development or perpetuation of harmful behaviors. Research has established a connection between social media use and increased health risk behaviors. This six-wave exploratory longitudinal study investigated the associations between active social media use, hazardous alcohol use, and problem gambling among adult social media users. METHODS: Data were collected via surveys in 6-month intervals, starting in March-April 2021 (T1: N = 1530; Mage = 46.67; SD = 16.42; 50.33% male). Of the T1 respondents, 58.10% participated in T6 (n = 889). Measures included the frequency of use of different social media platforms, the 3-item Alcohol Use Disorders Identification Test (AUDIT-C), and the Problem Gambling Severity Index (PGSI). Hybrid multilevel regression models were used for analyses. RESULTS: We found positive within-person effects of weekly Facebook use and between-person effects of weekly use of Facebook, TikTok, and gambling-related online communities on drinking. These results suggest an increase in hazardous alcohol consumption over time among the platforms' active users. Weekly Instagram use had a negative between-person effect on hazardous alcohol use. Individuals using TikTok or gambling communities weekly were more prone to problem gambling compared to non-weekly users. CONCLUSIONS: There are risks involved in the active use of some social media services among adult users. Prevention work, including digital health interventions, should be targeted according to the appropriate user group.

Better social reversal learning is associated with a more social approach across time.

Flexibly updating behaviors towards others is crucial for adaptive social functioning. Previous studies have found that difficulties in flexibly updating behaviors are associated with social anxiety (SA). However, it is unclear whether such difficulties relate to actual social behaviors. The current study investigated the relationships between negative-to-positive social reversal learning, social approach behavior, and SA across time. Participants (MTurk, Time 1 = 275, Time 2 = 126, 16 weeks later) completed a performance-based social reversal-learning task. In the initial phase, participants learned that interactions with certain individuals are associated with negative outcomes, whereas interactions with other individuals are associated with positive outcomes. In the reversal phase, these associations were reversed, requiring participants to update their behaviors. The relationships between the performance in the task, SA severity, and social approach behavior reported by participants were assessed cross-sectionally and longitudinally. We found that negative-to-positive updating was negatively associated with SA severity. Furthermore, negative-to-positive updating was positively correlated with social approach behavior, both cross-sectionally and prospectively. Hence, individuals with better negative-to-positive updating at Time 1 reported significantly more social approach behaviors across time. The results support the role of negative-to-positive updating as a mechanism associated with SA and social approach, advancing and refining interpersonal and cognitive theories of SA.

Longitudinal assessment of psychological distress and its determinants in a sample of firefighters based in Montreal, Canada.

Introduction: Firefighters face elevated risks of common mental health issues, with distress rates estimated at around 30%, surpassing those of many other occupational groups. While exposure to potentially traumatic events (PTEs) is a well-recognized risk factor, existing research acknowledges the need for a broader perspective encompassing multidimensional factors within the realm of occupational stress. Furthermore, this body of evidence heavily relies on cross-sectional studies. This study adopts an intensive longitudinal approach to assess psychological distress and its determinants among firefighters. Methods: Participants were recruited from 67 fire stations in Montreal, Canada, meeting specific criteria: full-time employment, smartphone ownership, and recent exposure to at least one PTE, or first responder status. Subjects underwent a telephone interview and were directed to use an app to report depressive, post-traumatic, and generalized anxiety symptoms every 2 weeks, along with work-related stressors, social support, and coping styles. Analyses involved 274 participants, distinguishing between those exceeding clinical thresholds in at least one distress measure (the "distressed" subgroup) and those deemed "resilient." The duration and onset of distress were computed for the distressed group, and linear mixed models were employed to evaluate determinants for each psychological distress variable. Results: Clinical psychological distress was observed in 20.7% of participants, marked by depressive, post-traumatic, and anxiety symptoms, often within the first 4-week reference period. Contextual factors (operational climate, social support, solitude) and individual factors (coping style, solitude and lifetime traumatic events in private life) exhibited more significant impacts on psychological distress than professional pressures within the firefighters' work environment. Discussion: This study reports lower rates of psychological distress than previous research, possibly attributable to sample differences. It highlights that reported symptoms often represent a combined and transient layer of distress rather than diagnosable mental disorders. Additionally, determinants analysis underscores the importance of interpersonal relationships and coping mechanisms for mental health prevention interventions within this worker group. The findings carry implications for the development of prevention and support programs for firefighters and similar emergency workers.

Examining the interaction between prenatal stress and polygenic risk for attention-deficit/hyperactivity disorder on brain growth in childhood: Findings from the DREAM BIG consortium.

This study explored the interactions among prenatal stress, child sex, and polygenic risk scores (PGS) for attention-deficit/hyperactivity disorder (ADHD) on structural developmental changes of brain regions implicated in ADHD. We used data from two population-based birth cohorts: Growing Up in Singapore Towards healthy Outcomes (GUSTO) from Singapore (n = 113) and Generation R from Rotterdam, the Netherlands (n = 433). Prenatal stress was assessed using questionnaires. We obtained latent constructs of prenatal adversity and prenatal mood problems using confirmatory factor analyses. The participants were genotyped using genome-wide single nucleotide polymorphism arrays, and ADHD PGSs were computed. Magnetic resonance imaging scans were acquired at 4.5 and 6 years (GUSTO), and at 10 and 14 years (Generation R). We estimated the age-related rate of change for brain outcomes related to ADHD and performed (1) prenatal stress by sex interaction models, (2) prenatal stress by ADHD PGS interaction models, and (3) 3-way interaction models, including prenatal stress, sex, and ADHD PGS. We observed an interaction between prenatal stress and ADHD PGS on mean cortical thickness annual rate of change in Generation R (i.e., in individuals with higher ADHD PGS, higher prenatal stress was associated with a lower rate of cortical thinning, whereas in individuals with lower ADHD PGS, higher prenatal stress was associated with a higher rate of cortical thinning). None of the other tested interactions were statistically significant. Higher prenatal stress may promote a slower brain developmental rate during adolescence in individuals with higher ADHD genetic vulnerability, whereas it may promote a faster brain developmental rate in individuals with lower ADHD genetic vulnerability.

Assessing depression recurrence, cognitive burden, and neurobiological homeostasis in late life: Design and rationale of the REMBRANDT Study.

Background: Late-life depression is characterized by disability, cognitive impairment and decline, and a high risk of recurrence following remission. Aside from past psychiatric history, prognostic neurobiological and clinical factors influencing recurrence risk are unclear. Moreover, it is unclear if cognitive impairment predisposes to recurrence, or whether recurrent episodes may accelerate brain aging and cognitive decline. The purpose of the REMBRANDT study (Recurrence markers, cognitive burden, and neurobiological homeostasis in late-life depression) is to better elucidate these relationships and identify phenotypic, cognitive, environmental, and neurobiological factors contributing to and predictive of depression recurrence. Methods: Across three sites, REMBRANDT will enroll 300 depressed elders who will receive antidepressant treatment. The goal is to enroll 210 remitted depressed participants and 75 participants with no mental health history into a two-year longitudinal phase focusing on depression recurrence. Participants are evaluated every 2 months with deeper assessments occurring every 8 months, including structural and functional neuroimaging, environmental stress assessments, deep symptom phenotyping, and two weeks of 'burst' ecological momentary assessments to elucidate variability in symptoms and cognitive performance. A broad neuropsychological test battery is completed at the beginning and end of the longitudinal study. Significance: REMBRANDT will improve our understanding of how alterations in neural circuits and cognition that persist during remission contribute to depression recurrence vulnerability. It will also elucidate how these processes may contribute to cognitive impairment and decline. This project will obtain deep phenotypic data that will help identify vulnerability and resilience factors that can help stratify individual clinical risk.

Comparing disease specific catastrophic cost estimates using longitudinal and cross-sectional designs: The example of tuberculosis.

BACKGROUND: There has been an increasing interest in assessing disease-specific catastrophic costs incurred by affected households as part of economic evaluations and to inform joint social/health policies for vulnerable groups. Although the longitudinal study design is the gold standard for estimating disease-specific household costs, many assessments are implemented with a cross-sectional design for pragmatic reasons. We aimed at identifying the potential biases of a cross-sectional design for estimating household cost, using the example of tuberculosis (TB), and exploring optimal approaches for sampling and interpolating cross-sectional cost data to estimate household costs. METHODS: Data on patient incurred costs, household income and coping strategies were collected from TB patients in Negros Occidental and Cebu in the Philippines between November 2018 and October 2020. The data collection tools were developed by adapting WHO Tuberculosis Patient Cost Surveys: A Handbook into a longitudinal study design. TB-specific catastrophic cost estimates were compared between longitudinal and simulated cross-sectional designs using different random samples from different times points in treatment (intensive and continuation phases). RESULTS: A total of 530 adult TB patients were enrolled upon TB diagnosis in this study. Using the longitudinal design, the catastrophic cost estimate for TB-affected households was 69 % using the output approach. The catastrophic cost estimates with the simulated cross-sectional design were affected by the reduction and recovery in household income during the episode of TB care and ranged from 40 to 55 %. CONCLUSION: Using longitudinally collected costs incurred by TB-affected households, we illustrated the potential limitations and implications of estimating household costs using a cross-sectional design. Not capturing changes in household income at multiple time points during the episode of the disease and estimating from inappropriate samples may result in biases that underestimates catastrophic cost.

Higher air pollution exposure in early life is associated with worse health among older adults: A 72-year follow-up study from Scotland.

Air pollution increases the risk of mortality and morbidity. However, limited evidence exists on the very long-term associations between early life air pollution exposure and health, as well as on potential pathways. This study explored the relationship between fine particle (PM2.5) exposure at age 3 and limiting long-term illness (LLTI) at ages 55, 65 and 75 using data from the Scottish Longitudinal Study Birth Cohort 1936, a representative administrative cohort study. We found that early life PM2.5 exposure was associated with higher odds of LLTI in mid-to-late adulthood (OR = 1.10, 95% CI: 1.06, 1.14 per 10 µg m-3 increment) among the 2085 participants, with stronger associations among those growing up in disadvantaged families. Path analyses suggested that 15-21% of the association between early life PM2.5 concentrations and LLTI at age 65 (n = 1406) was mediated through childhood cognitive ability, educational qualifications, and adult social position. Future research should capitalise on linked administrative and health data, and explore causal mechanisms between environment and specific health conditions across the life course.

Early adverse childhood experiences and preschoolers' attentional regulation: A latent class analysis.

BACKGROUND: Adverse childhood experiences (ACEs) profoundly disrupt preschoolers' attentional regulation development. Different patterns of ACEs may be associated with different attentional regulation outcomes. OBJECTIVE: Drawing from developmental systems theory and attachment theory, this study aimed to identify distinct patterns of early ACEs at age three and examined the associations of these patterns with preschoolers' attentional regulation at age five. PARTICIPANTS AND SETTING: This study used the two waves of longitudinal data from the Future of Families and Child Wellbeing Study (N = 4457). METHODS: First, this study applied latent class analysis (LCA) across nine indicators of ACEs at age three. Second, class membership was examined for associations with preschoolers' attentional regulation at age five. RESULTS: LCA identified four latent classes of ACEs: separation (41.2 %), parental incarceration (33 %), family dysfunction (20.8 %), and child abuse (5 %). Children in the child abuse class exhibited lower levels of attentional regulation than those in the family dysfunction class (0.33 standard deviation difference, p < .01) or separation class (0.48 standard deviation difference, p < .001). Children in the parental incarceration class demonstrated lower levels of attentional regulation than those in the separation class (0.63 standard deviation difference, p < .001). CONCLUSIONS: Findings provide implications for the need to prevent early child abuse and incorporate trauma-informed intervention programs to support preschoolers' attentional regulation during school-entry age.

Trajectories of Competitive Employment of Autistic Adults through Late Midlife.

Autistic adults experience challenges in maintaining employment; however, little is known about patterns of competitive employment through late midlife. This longitudinal study examined the change in hours of competitive employment for a cohort of autistic adults over a 22-year period. The study's aims were to provide a fine-grained analysis of competitive employment patterns, to determine whether there was age-related change, and to test whether trajectories differed between those with and without intellectual disability (ID). Using an accelerated longitudinal design, trajectories of hours of competitive employment were estimated from young adulthood through late midlife in a community-based cohort (n = 341; 1327 observations). Results indicated a significant curvilinear trajectory of age-related change in hours of competitive employment, with differences between those with and without ID. For those without ID, the number of competitive employment hours increased from young adulthood until early midlife, then leveled off and decreased into late midlife. For those with ID, engagement in competitive employment was low throughout. Although competitive employment is just one option for vocational engagement, it is a goal often articulated by autistic adults who seek entry into the general workforce. The present research reveals their degree of engagement in the competitive workforce across the decades of adulthood.

Exploring the Potential of a Behavior Theory-Informed Digital Intervention for Infant Fall Prevention: Mixed Methods Longitudinal Study.

BACKGROUND: Falls are the most common hospitalized injury mechanism in children aged ≤1 years, and currently, there are no targeted prevention interventions. The prevention of falls in children of this age requires changes in the behavior of their caregivers, and theoretically informed digital behavior change interventions (DBCIs) may provide a unique mechanism for achieving effective intervention. However, user acceptance and the ability of DBCIs to effect the required changes in behavior are critical to their likelihood of success. OBJECTIVE: This study aims to evaluate a behavior theory-informed digital intervention developed following a user-centered approach for user experience, the potential for this intervention to prevent infant falls, and its impact on behavioral drivers underpinning fall risk in young children. METHODS: Parents of infants aged <1 year were recruited and asked to use the intervention for 3 months. A pre-post longitudinal design was used to examine the change in the potential to reduce the risk of falls after a 3-month exposure to the intervention. Postintervention data on behavioral drivers for fall prevention, user acceptability, and engagement with the app were also collected. Interviews were conducted to explore user experiences and identify areas for further improvement of the intervention. RESULTS: A total of 62 parents participated in the study. A statistically significant effect on the potential to reduce falls was observed after the intervention. This effect was higher for new parents. Parents agreed that the intervention targeted most of the target behavior drivers. The impact of behavior drivers and intervention on the potential for fall prevention had a positive correlation. The intervention demonstrated good levels of acceptability. Feedback from participants was mostly positive, and the primary area identified for further improvement was widening the scope of the intervention. CONCLUSIONS: This study demonstrated the promise of a newly developed digital intervention to reduce the risk of infant falls, particularly among new parents. It also showed a positive influence of the DBCI on the drivers of parental behaviors that are important for fall reduction among infants. The acceptability of the app was high, and important insights were gained from users about how to further improve the app.

100 days of Adolescence: Elucidating Externalizing Behaviors Through the Daily Assessment of Inhibitory Control.

Inhibitory control is a transdiagnostic risk factor for externalizing behaviors, particularly during adolescence. Despite advances in understanding links between inhibitory control and externalizing behaviors across youth on average, significant questions remain about how these links play out in the day-to-day lives of individual adolescents. The goals of the current study were to: (1) validate a novel 100-occasion measure of inhibitory control; (2) assess links between day-to-day fluctuations in inhibitory control and individual differences in externalizing behaviors; and (3) illustrate the potential of intensive longitudinal studies for person-specific analyses of adolescent externalizing behaviors. Participants were 106 youth (57.5% female, Mage = 13.34 years; SDage = 1.92) who completed a virtual baseline session followed by 100 daily surveys, including an adapted Stroop Color Word task designed to assess inhibitory control. Results suggested that the novel task was generally reliable and valid, and that inhibitory control fluctuated across days in ways that were meaningfully associated with individual differences in baseline impulsive behaviors. Results of illustrative personalized analyses suggested that inhibitory control had more influence in the daily networks of adolescents who used substances during the 100 days than in a matched set of adolescents who did not. This work marks a path forward in intensive longitudinal research by validating a novel inhibitory control measure, revealing that daily fluctuations in inhibitory control may be a unique construct broadly relevant to adolescent externalizing problems, and at the same time, highlighting that links between daily inhibitory control and impulsive behaviors are adolescent-specific.