Key symptoms of anxiety include experiencing unpleasant emotions and hyperarousal. Growing evidence suggests that delayed affective recovery (DAR) from daily stressors plays a role in their maintenance and development on a day-to-day basis. We examined whether DAR is linked to current and future anxiety symptoms, independently of depressive symptoms. Self-reported anxiety and depressive symptoms were assessed at Wave 1 (N = 1,031) and approximately 2.5 years later at Wave 2 (N = 171) in a community sample of Flemish adolescents. Additionally, at Wave 1, the experience sampling method was used to obtain assessments of momentary affect and to infer stressful occurrences, with data collected 10 times a day, for 6 days. Using affective experience sampling method data, we constructed two variables, that is, affective valence and arousal, reflecting the (un)pleasantness and (hyper)arousal associated with emotions. The time interval for recovery was estimated using parametric survival analysis. Prospective associations were tested with multiple regression. Slower valence recovery was associated with higher concurrent anxiety symptoms. A similar association was present for the arousal recovery, however only when depressive symptoms were added to the model. We found no prospective association between the speed of valence nor arousal recovery at Wave 1 and anxiety symptoms at Wave 2. The results suggest that DAR is linked to current anxiety symptoms but does not predict their development 2.5 years later. Our findings provide insights into possible processes underlying the key features of anxiety and help identify the moments of vulnerability in the daily lives of youth.

The COVID-19 pandemic is believed to have strongly impacted adolescents' mental health through limiting their day-to-day social lives. However, little is known about the role of (social) risk/protective factors and adolescent mental health. Subclinical psychopathology, and risk and protective factors of n = 173 adolescents (T1 mean age = 16.0; 89% girls) were assessed prepandemic and early-pandemic (T1: 2018/2019; T2: May 2020). Daily-life social interactions were assessed in 6-day experience sampling periods. Correcting for age, multilevel analyses revealed declines in general psychopathology and anxiety symptoms; fewer face-to-face social interactions, more online social interactions; and higher-quality face-to-face interactions during the pandemic than before. Negative associations between psychopathology and the quality of face-to-face peer and family interactions were stronger during the pandemic than prepandemic. The results reflect that, early in the pandemic, the mental health impact on adolescents may have been limited. High-quality face-to-face interactions with family and peers seemed particularly powerful in keeping adolescents resilient.

Childhood adversity is known to predispose to a wide array of psychopathology in adolescence and early adulthood. Identity development, being a crucial developmental task during adolescence, has been suggested to affect this association. Nonetheless, research on the role of identity processes is scarce. The current study aims to investigate how identity processes of exploration and commitment may impact the association between childhood adversity and psychopathology. We cross-sectionally investigated the association between childhood adversity, identity processes (i.e., exploration in breadth and depth, commitment making, identification with commitment and ruminative exploration) and depressive, anxiety and psychosis symptoms in 869 Flemish adolescents between 14 and 20 years old (mean = 15.52, SD = 1.28). Childhood adversity was associated with increased ruminative exploration, which itself was associated with increased psychopathology. On the other hand, commitment making, identification with commitment and exploration in breadth were associated with decreased psychopathology. Processes of exploration in breadth and commitment making attenuated the association between childhood adversity and psychopathology. Moreover, identification with commitment and ruminative exploration potentially mediated this association. These findings underscore the importance of healthy identity processes in adolescents, with and without exposure to childhood adversity. Measures of identity structure and identity processes should be combined to fully capture identity.

Adolescence is a critical period for self-harm thoughts and behaviours (SHTBs) and loneliness is an important risk factor. However, no research has investigated how loneliness is associated with adolescent SHTBs in real time and whether this association is influenced by parent-child attachment relationships, which correlate with both loneliness and SHTBs. We used Experience Sampling Methodology (ESM) and self-report questionnaires to examine the role of loneliness and parent-child attachment in SHTBs in a general population adolescent sample (N=1602). Multilevel analyses provide evidence for loneliness as a short-term risk factor for self-harm thoughts, and the emotion regulation function of self-harm behaviours (i.e., downregulation of loneliness). The relationship between loneliness and SHTBs was stronger for those with a more insecure paternal and maternal attachment relationships. These results illuminate when (i.e., moments of loneliness) and why (i.e., loneliness downregulation) adolescents think about and engage in self-harm, offering critical guidance to clinicians and researchers.

BACKGROUND:The COVID-19 pandemic is assumed to have had a large impact on the mental health of adolescents. Finding out for which youth the mental health impact was largest is imperative for strengthening future crisis responses. In this study, we aimed to assess the impact of the pandemic on the mental health of different sociodemographic groups of general population adolescents in Flanders, Belgium. METHODS:Adolescents were tested for the SIGMA study, at W1 (n=1913; mean age=13.8; 63.1% female; 2018/2019); W2 (n=272; mean age=16.5; 74.0% female; 2020); and W3 (n=227; mean age=18.0; 78.4% female; 2022/2023). Subclinical anxiety, depression, psychoticism, and general psychopathology were measured with the Brief Symptom Inventory-53. Multilevel linear regression models with imputed data sets were used to test cross-wave differences in each psychopathology outcome (controlling for age-related increases), effects of time since the beginning of the pandemic and stringency of pandemic-related measures, and effects of several sociodemographic predictors on levels and changes in psychopathology (from W1 to W2, and from W1 to W3). RESULTS:Results indicated limited overall early increases in psychopathology (only for depression from W1 to W2), and some decreases in psychopathology levels from W1 to W3 (for anxiety and general psychopathology). Girls and those reporting same-gender attraction reported higher levels of nearly all symptoms. CONCLUSION:Although most youth in this sample were resilient during the COVID-19 pandemic, some groups consistently showed high psychopathology levels. Attention is still needed for groups that were at risk before the pandemic, notably, LGTBQIA+ youth.

Introduction: Childhood adversity may result in a negative expectation of future interactions with others, also referred to as ‘threat anticipation’. It may also negatively impact on identity development, which subsequently may influence how individuals deal with their environment. Here, we examine the hypotheses that 1) identity development is associated with threat anticipation, and 2) that identity confusion, in the presence of childhood adversity, has a synergistic effect on the development of threat anticipation. Methods: 1913 adolescents from the general population (mean age = 13.8 years, SD = 1.86, range = 11-20) completed self-report questionnaires assessing exposure to childhood adversity, identity development and threat anticipation. Results: Identity development was significantly associated with threat anticipation in the expected direction: identity synthesis was associated with reduced anticipation of threat (β = -.0013, p < .001), whereas identity confusion was association with increased threat anticipation (β = .0017, p < .001). Furthermore, childhood adversity was positively associated with threat anticipation (β = .0018, p < .001). However, no evidence for an interaction effect of identity on the association between childhood adversity and threat anticipation was found.Conclusion: The current study illustrates the importance of exposure to childhood adversity and identity development for the anticipation of threat. Identity development however did not moderate the association between childhood adversity and threat anticipation, suggesting childhood adversity and identity development have an additive rather than synergistic effect on threat anticipation. Further research is needed to clarify how both factors influence each other within a developmental framework.

BACKGROUND:Research suggests that most mental health conditions have their onset in the critically social period of adolescence. Yet, we lack understanding of the potential social processes underlying early psychopathological development. We propose a conceptual model where daily-life social interactions and social skills form an intermediate link between known risk and protective factors (adverse childhood experiences, bullying, social support, maladaptive parenting) and psychopathology in adolescents - that is explored using cross-sectional data. METHODS:N = 1913 Flemish adolescent participants (Mean age = 13.8; 63% girls) were assessed as part of the SIGMA study, a large-scale, accelerated longitudinal study of adolescent mental health and development. Self-report questionnaires (on risk/protective factors, social skills, and psychopathology) were completed during class time; daily-life social interactions were measured during a subsequent six-day experience-sampling period. RESULTS:Registered uncorrected multilevel linear regression results revealed significant associations between all risk/protective factors and psychopathology, between all risk/protective factors and social processes, and between all social processes and psychopathology. Social processes (social skills, quantity/quality of daily social interactions) were uniquely predicted by each risk/protective factor and were uniquely associated with both general and specific types of psychopathology. For older participants, some relationships between social processes and psychopathology were stronger. CONCLUSIONS:Unique associations between risk/protective factors and psychopathology signify the distinct relevance of these factors for youth mental health, whereas the broad associations with social processes support these processes as broad correlates. Results align with the idea of a social pathway toward early psychopathology, although follow-up longitudinal research is required to verify any mediation effect.

Purpose: The COVID-19 pandemic is assumed to have had a large impact on the mental health of adolescents. Finding out for which youth the mental health impact was largest is imperative for strengthening future crisis responses. In this study, we aimed to assess the impact of the pandemic on the mental health of different sociodemographic groups of general population adolescents in Flanders, Belgium. Methods: Adolescents were tested for the SIGMA study, at W1 (n=1913; mean age=13.8; 63.1% female; 2018/2019); W2 (n=272; mean age=16.5; 74.0% female; 2020); and W3 (n=227; mean age=18.0; 78.4% female; 2022/2023). Subclinical anxiety, depression, psychoticism, and general psychopathology were measured with the Brief Symptom Inventory-53. Multilevel linear regression models with imputed data sets were used to test cross-wave differences in each psychopathology outcome (controlling for age-related increases), effects of time since the beginning of the pandemic and stringency of pandemic-related measures, and effects of several sociodemographic predictors on levels and changes in psychopathology (from W1 to W2, and from W1 to W3). Results: Results indicated limited overall early increases in psychopathology (only for depression from W1 to W2), and some decreases in psychopathology levels from W1 to W3 (for anxiety and general psychopathology). Girls and those reporting same-gender attraction reported higher levels of nearly all symptoms. Conclusion: Although most youth in this sample were resilient during the COVID-19 pandemic, some groups consistently showed high psychopathology levels. Attention is still needed for groups that were at risk before the pandemic, notably, LGTBQIA+ youth.

Background and Hypothesis Childhood adversity is associated with a myriad of psychiatric symptoms, including psychotic experiences (PEs), and with multiple psychological processes that may all mediate these associations. Study Design Using a network approach, the present study examined the complex interactions between childhood adversity, PEs, other psychiatric symptoms, and multiple psychological mediators (ie, activity-related and social stress, negative affect, loneliness, threat anticipation, maladaptive cognitive emotion regulation, attachment insecurity) in a general population, adolescent sample (n = 865, age 12-20, 67% female). Study Results Centrality analyses revealed a pivotal role of depression, anxiety, negative affect, and loneliness within the network and a bridging role of threat anticipation between childhood adversity and maladaptive cognitive emotion regulation. By constructing shortest path networks, we found multiple existing paths between different categories of childhood adversity and PEs, with symptoms of general psychopathology (ie, anxiety, hostility, and somatization) as the main connective component. Sensitivity analyses confirmed the robustness and stability of the networks. Longitudinal analysis in a subsample with Wave 2 data (n = 161) further found that variables with higher centrality (ie, depression, negative affect, and loneliness) better predicted follow-up PEs. Conclusions Pathways linking childhood adversity to PEs are complex, with multifaceted psychological and symptom-symptom interactions. They underscore the transdiagnostic, heterotypic nature of mental ill-health in young people experiencing PEs, in agreement with current clinical recommendations.

Background: Adolescent solitude was drastically impacted by the COVID-19 pandemic. As solitude is crucial for adolescent development through its association with both positive and negative developmental outcomes, it is critical to understand how adolescents’ daily-life solitary experiences changed as a result of the pandemic.Methods: Using three waves of Experience Sampling Method data from a longitudinal study, we compared adolescents’ daily-life solitary experiences in the early (nT1=100; MAge=16.1; SDAge=1.9; 93% girls) and mid-pandemic (nT2=204; MAge=16.5; SDAge=2.0; 79% girls) to their pre-pandemic experiences.Results: We found that adolescents with lower levels of pre-pandemic social support and social skills reported wanting to be alone less and feeling like an outsider more at both time points during the pandemic. In the mid-pandemic wave, adolescents with higher levels of pre-pandemic social support and social skills reported decreases in positive affect compared to the pre-pandemic wave.Conclusion: This study shows that adolescents’ daily-life solitary experiences worsened throughout the COVID-19 pandemic. There should be continued concern for the wellbeing of all adolescents, not only those already at risk, as effects of the pandemic on mental health might only manifest later.

INTRODUCTION Sleep quality is closely linked with mental health. Two factors that influence sleep are coping style and locus of control, yet these have not been investigated in daily life. In this study, we examined associations between coping styles and sleep quality in daily life and the potential mediating effect of daily locus of control in a sample of youth, a group particularly vulnerable to developing psychopathology. METHODS Three hundred and seventy-nine youths from the TwinssCan study participated in an Experience Sampling study, assessing sleep quality as well as state locus of control over the most negative event from the previous day. Participants also completed the Utrecht Coping List, which assessed engagement, disengagement, and emotion-focused coping. RESULTS Disengagement, "passive reaction," and emotion-focused coping were associated with lower daily sleep quality. State locus of control did not mediate any effects of coping styles on quality of sleep. CONCLUSIONS Disengagement, "passive reaction," and emotion-focused coping were associated with decreased sleep quality during several consecutive days, which may put youths at risk for developing future insomnia, and strain their mental well-being over time. Thus, there may be value in asking about coping when a young individual presents with sleep problems; however, impaired coping when sleeping poorly should also be considered.

The Perceptual Crossing Experiment (PCE) captures the capacity for social contingency detection using real-time social interaction dynamics but has not been externally validated. We tested ecological and convergent validity of the PCE in a sample of 208 adolescents from the general population, aged 11 to 19 years. We expected associations between PCE performance and (a) quantity and quality of social interaction in daily life, using Experience Sampling Methodology (ESM; ecological validity) and (b) self-reported social skills using a questionnaire (convergent validity). We also expected PCE performance to better explain variance in ESM social measures than self-reported social skills. Multilevel analyses showed that only self-reported social skills were positively associated with social experience of company in daily life. These initial results do not support ecological and convergent validity of the PCE. However, fueled by novel insights regarding the complexity of capturing social dynamics, we identified promising methodological advances for future validation efforts.

IntroductionChildhood adversity is a major risk factor for psychiatric disorders and has especially been associated with an admixture of depressive, anxiety and psychosis symptoms. Identity formation, a main developmental task during adolescence, may be impacted by these adverse experiences and act as an important process in the association between childhood adversity and psychopathology.MethodsWe investigated the association between childhood adversity, identity formation, and depressive, anxiety and psychosis symptoms cross-sectionally in 1913 Flemish adolescents between 11 and 20 years old (mean = 13.76, SD = 1.86). Adolescents completed questionnaires during the first wave of the SIGMA study between January 2018 and May 2019.ResultsChildhood interpersonal adversity was associated with increased identity confusion and decreased identity synthesis. Additionally, identity confusion was associated with increased self-reported levels of psychopathology and potentially mediated the association between childhood adversity and psychopathology. ConclusionThis study highlights the importance of promoting healthy identity formation in adolescents with and without exposure to adverse childhood experiences.

Key symptoms of anxiety include experiencing unpleasant emotions and hyperarousal. Growing evidence suggests the role of delayed affective recovery from stress (DAR) in their maintenance and development on a day-to-day basis. We aimed to investigate whether DAR is linked to current and future anxiety symptoms, independently of depressive symptoms. Self-reported anxiety and depressive symptoms were assessed twice: at Wave 1 (N=1031) and approximately 2.5 years later at Wave 2 (N=171) in a community sample of adolescents. Additionally, at Wave 1, Experience Sampling Method (ESM) was used. Participants reported their momentary affect and stressful occurrences 10 times a day, for six days. Using ESM data and a subtraction method, we construed two variables, i.e., affective valence and arousal reflecting the (un)pleasantness and (hyper)arousal associated with emotions. The time interval for affective recovery was estimated using parametric survival analysis. Prospective associations were tested with multiple regression. Slower valence recovery was associated with higher concurrent anxiety symptoms (p&lt;.05) and this association remained present when controlling for depressive symptoms (p&lt;.05). The same association was present for the arousal recovery, however only when depressive symptoms were added to the model (p&lt;.05). We found no prospective association between the speed of valence nor arousal recovery at Wave 1 and anxiety symptoms at Wave 2. Our results suggest that DAR may be a concomitant process contributing to the maintenance of key anxiety symptoms, but not to their development. Our findings help identify the moments in the daily lives of youth, where potential interventions could be implemented.

Emotion regulation in daily life can serve as a risk or resilience factor during times of crisis. Using the experience sampling method, the current study investigated rumination, savoring, and sharing with others in response to positive and negative events during the early COVID-19 pandemic lockdown measures among adolescents (N = 110, aged 13-20, 89% female). For six days, adolescents reported the intensity and valence of events throughout the day and how much they ruminated and shared about negative events and savored and shared about positive events. We aimed to conceptually replicate pre-pandemic findings and found that relationships between emotion regulation and event intensity were largely replicated: During the pandemic, higher intensity of negative events was associated with ruminating more and higher intensity of positive events was associated with savoring more and sharing more about them. Symptoms of psychopathology (anxiety, depression, and psychoticism) were not associated with ruminating about negative events, contrary to pre-pandemic observations, or sharing about negative events. However, psychopathology symptoms were positively associated with savoring positive events. The current results highlight the importance of context in daily life emotion regulation and suggest that adaptive emotion regulation may look different for adolescents during a major disruption to daily life.

Background: Previous research suggests attachment is a vulnerability factor for self-harm thoughts and behaviors in adults. Yet, few studies have investigated this relationship during adolescence, although adolescence is a critical period for changes in attachment relationships and self-harm onset. Whether and how attachment relates to self-harm thoughts and behaviors as measured in daily life is also unknown. Aims: To investigate whether and how paternal, maternal, and peer attachment are associated with lifetime and current adolescent self-harm thoughts and behaviors. Additionally, to examine how different attachment bonds interact in relation to lifetime and current adolescent self-harm thoughts and behaviors. Method: Pre-existing data from N = 1,913 adolescents of the SIGMA study were used. Attachment and lifetime history of self-harm thoughts and behaviors were measured via retrospective questionnaires. Current self-harm thoughts and behaviors were assessed 10 times per day for 6 days using the experience sampling method (ESM). Results: Paternal and maternal attachments were associated with lifetime self-harm thoughts and behaviors and current self-harm thoughts. No significant associations were found between peer attachment and self-harm outcomes. Limitations: Some analyses were underpowered. Conclusion: Our results highlight the importance of parent-child attachment relationships, which may be intervention targets for prevention and treatment of adolescent self-harm.

Identifying adolescents for whom social withdrawal may form a specific risk, is crucial for improving prevention and early intervention efforts. Model-based clustering on daily-life data from n=1312 Flemish general population adolescents (65% female, MAge=13.8, n=296 identifying with non-Belgian nationality or ethnicity) identified four groups with different experiences of social withdrawal and being in company. One cluster reported overall positive experiences, one cluster reported overall negative experiences and two clusters reported mixed experiences: positive in-company experiences and negative social withdrawal experiences, and vice versa. Group membership was significantly associated with differences in psychosocial factors, including depression, anxiety, and psychosis. This suggests that daily-life social and non-social experiences are a useful indicator to differentiate between adolescents and identify those potentially at risk.

Childhood adversity is associated with psychopathology. First evidence in adults suggests that threat anticipation, i.e., an enhanced anticipation of unpleasant events creating an enduring sense of threat, may be a putative mechanism linking childhood adversity to psychopathology. This study aimed to test the indirect effect of childhood adversity on psychopathology via threat anticipation in a large community sample of adolescents. We measured childhood trauma and bullying victimization (as indicators of childhood adversity), threat anticipation, general psychopathology and prodromal psychotic symptoms in adolescents aged 12–16 years (full sample size N = 1682; minimum sample size in the complete case sample N = 449) in wave I of the SIGMA study. We found strong evidence that childhood adversity (e.g. childhood trauma, adj. β (aβ) = 0.54, p < .001) and threat anticipation (e.g. aβ = 0.36, p < .001) were associated with general psychopathology and prodromal psychotic symptoms. Moreover, there was evidence that the association between childhood adversity, general psychopathology and prodromal psychotic symptoms is mediated via pathways through threat anticipation (e.g. childhood trauma, aβ indirect effect = 0.13, p < .001). Threat anticipation may be a potential mechanism linking childhood adversity and psychopathology in adolescents.

Social withdrawal is often presented as overall negative, with a focus on loneliness and peer exclusion. However, social withdrawal is also a part of normative adolescent development, which indicates that groups of adolescents potentially experience social withdrawal differently from one another. This study investigated whether different groups of adolescents experienced social withdrawal in daily life as positive versus negative, using experience sampling data from a large-scale study on mental health in general population adolescents aged 11 to 20 (n = 1913, M-Age = 13.8, SDAge = 1.9, 63% female) from the Flemish region in Belgium. Two social withdrawal clusters were identified using model-based cluster analysis: one cluster characterized by high levels of positive affect and one cluster characterized by high levels of negative affect, loneliness and exclusion. Logistic regression showed that boys had 66% decreased odds of belonging to the negative cluster. These results show that daily-life social withdrawal experiences are heterogeneous in adolescence, which strengthens the view that, both in research and clinical practice, social withdrawal should not be seen as necessarily maladaptive.

BACKGROUND Ambulatory monitoring is gaining popularity in mental and somatic health care to capture an individual's wellbeing or treatment course in daily-life. Experience sampling method collects subjective time-series data of patients' experiences, behavior, and context. At the same time, digital devices allow for less intrusive collection of more objective time-series data with higher sampling frequencies and for prolonged sampling periods. We refer to these data as parallel data. Combining these two data types holds the promise to revolutionize health care. However, existing ambulatory monitoring guidelines are too specific to each data type, and lack overall directions on how to effectively combine them. METHODS Literature and expert opinions were integrated to formulate relevant guiding principles. RESULTS Experience sampling and parallel data must be approached as one holistic time series right from the start, at the study design stage. The fluctuation pattern and volatility of the different variables of interest must be well understood to ensure that these data are compatible. Data have to be collected and operationalized in a manner that the minimal common denominator is able to answer the research question with regard to temporal and disease severity resolution. Furthermore, recommendations are provided for device selection, data management, and analysis. Open science practices are also highlighted throughout. Finally, we provide a practical checklist with the delineated considerations and an open-source example demonstrating how to apply it. CONCLUSIONS The provided considerations aim to structure and support researchers as they undertake the new challenges presented by this exciting multidisciplinary research field.