Course Of Adolescence Research Articles

Development of ADHD: Etiology, Heterogeneity, and Early Life Course.

ADHD represents a powerful entry point for developmental approaches to psychopathology due to its major role in early emergence of major life problems. One key issue concerns the role of early environmental risks in etiology and maintenance in the context of genetic liability. Here, psychosocial aspects of development need more attention. A second key issue is that phenotypic heterogeneity requires better resolution if actionable causal mechanisms are to be effectively identified. Here, the interplay of cognition and emotion in the context of a temperament lens is one helpful way forward. A third key issue is the poorly understood yet somewhat striking bifurcation of developmental course in adolescence, when a subgroup seem to have largely benign outcomes, while a larger group continue on a problematic path. A final integrative question concerns the most effective conceptualization of the disorder in relation to broader dysregulation. Key scientific priorities are noted.

Is personality stable inadolescence? Disentangling time-invariant and time-varying factors of personality inatrait-state-occasion model.

This study applied trait-state-occasion (TSO) modelling to investigate the extent to which inter-individual differences in personality were accounted for by time-invariant and time-varying factors during adolescence. The participants were 753 high school students, and only 661 students were followed for 4 years. The mean age in the first year was 15.23 years and 52.8% were females. The results showed that the full TSO model had the best representation of adolescent personality, and the means of the proportions of variance explained by trait factors for the Big Five ranged between 56% and 83%, suggesting that inter-individual differences in personality are mainly accounted for by stable trait variance over the course of adolescence. Furthermore, the five dimensions of personality differed not only in the amounts of trait variance but also in the stability of time-varying factors. These findings have significant implications for personality research.

Responsibility sharing for adolescents with type 1 diabetes: A scoping review.

The term 'Responsibility Sharing', albeit poorly defined, has emerged from the diabetes literature, to describe a distinct mechanism for comprehensively managing the characteristic shift in responsibility that underpins the transition to self-management for adolescents. A scoping review, following the PRISMA-ScR guidelines, distilled the literature from seven databases to answer the questions: What is responsibility sharing? Who are the key stakeholders? What factors affect responsibility transaction? What are its recognized outcomes? How is responsibility shared? Responsibility sharing is a transactional arrangement between youth and their caregiver/s that functions to repeatedly and flexibly apply ownership to the management of diabetes care tasks, across the course of adolescence. In the main, responsibility sharing was associated with better metabolic and/or psychosocial outcomes. Effective responsibility sharing was seen as being responsive to adolescent capacity and driven by autonomy supportive, sustained communication patterns that enable mutually agreeable responsibility assumption by all stakeholders. Different perspectives on responsibility sharing for adolescents with Type 1 diabetes, and the lack of a universal definition, have led to discordance within the literature about its operationalization and measurement. This paper proposes a definition of responsibility sharing for future researchers to apply.

Compulsivity is linked to reduced adolescent development of goal-directed control and frontostriatal functional connectivity

A characteristic of adaptive behavior is its goal-directed nature. An ability to act in a goal-directed manner is progressively refined during development, but this refinement can be impacted by the emergence of psychiatric disorders. Disorders of compulsivity have been framed computationally as a deficit in model-based control, and have been linked also to abnormal frontostriatal connectivity. However, the developmental trajectory of model-based control, including an interplay between its maturation and an emergence of compulsivity, has not been characterized. Availing of a large sample of healthy adolescents (n = 569) aged 14 to 24 y, we show behaviorally that over the course of adolescence there is a within-person increase in model-based control, and this is more pronounced in younger participants. Using a bivariate latent change score model, we provide evidence that the presence of higher compulsivity traits is associated with an atypical profile of this developmental maturation in model-based control. Resting-state fMRI data from a subset of the behaviorally assessed subjects (n = 230) revealed that compulsivity is associated with a less pronounced change of within-subject developmental remodeling of functional connectivity, specifically between the striatum and a frontoparietal network. Thus, in an otherwise clinically healthy population sample, in early development, individual differences in compulsivity are linked to the developmental trajectory of model-based control and a remodeling of frontostriatal connectivity.

Representative Percentile Curves of Physical Fitness From Early Childhood to Early Adulthood: The MoMo Study.

Introduction: Monitoring of physical fitness in youth is important because physical fitness is a summative indicator of health. From a developmental and preventive perspective, physical fitness levels are relatively stable from childhood to early adulthood. Thus, it is important to monitor physical fitness on a population based level being able to intervene at early stages (1). In order to reliably assess and evaluate the physical fitness of youth, a reliable system of standard values based on representative data is required. The aim of this analysis is to report sex- and age-specific physical fitness percentile curves from childhood to early adulthood in a nationwide sample in Germany.Methods: We use data from the nationwide representative Motorik Modul (MoMo) Study in Germany (data collection wave 1: 2009–2012; age: 4–23 years; n = 3,742; 50.1% female). Physical fitness was assessed by means of the MoMo test profile covering four dimensions of physical fitness (strength, endurance, coordination, and flexibility) and including eight physical fitness items. Percentile curves were fitted using the LMS transformation method of Cole and Green.Results: Standardized age- and sex-specific physical fitness percentiles were calculated for eight items: ergometric endurance testing, standing long jump, push-ups, sit-ups, jumping side-ways, balancing backwards, static stand, and stand and reach test. The physical fitness curves differ according to gender and the fitness dimension. Physical fitness improvements with age are linear (e.g., max. strength) or curvilinear (e.g., coordination) and have their stagnation points at different times over the course of adolescence.Discussion: Our results provide for the first time sex- and age-specific physical fitness percentile curves for Germany from 4 to 17 years. Differences in curve-shapes indicating a timed and capacity-specific physical fitness development. Nationwide German physical fitness percentiles can be useful in comparing different populations (e.g., cross-country), reporting secular trends, comparing special groups, and to evaluate physical fitness interventions.

ОСОБЛИВОСТІ СОЦІАЛЬНО-ПСИХОЛОГІЧНОЇ АДАПТАЦІЇ ОСОБИСТОСТІ ЮНАЦЬКОГО І ДОРОСЛОГО ВІКУ В НЕФОРМАЛЬНІЙ СУБКУЛЬТУРІ

У статті подано результати дослідження, які дозволяють розширити наукове розуміння адаптації та розглядати її не лише, як процес пристосування до нових обставин, а й як важливий процес особистісного зростання і розвитку. Презентоване дослідження мало на меті виявлення особливостей соціально-психологічної адаптації особистості юнацького та дорослого віку чоловічої й жіночої статі в неформальній субкультурі, порівняно з респондентами, які до неї не належать. Метод дослідження – опитувальник соціально-психологічної адаптації (СПА) К. Роджерса та Р. Даймонд. Вибірка складалася з юнацького і дорослого віку чоловічої й жіночої статі. За допомогою процедур рандомізації було створено дві групи респондентів, кожна з яких складалася зі 160 осіб, які були представниками, відповідно, неформальних і формальних груп.Розкрито результати вивчення інтегральної соціально-психологічної адаптації учасників неформальних і формальних груп та її окремих складників. За переважною більшістю складових соціально-психологічної адаптації, активні учасники неформальних угруповань мають вищі показники, порівняно з пересічними респондентами, зокрема, за шкалами «адаптивність», «прийняття себе», «емоційний комфорт», «внутрішній контроль», «прагнення до домінування», «конформність», «ескапізм», проте нижчі показники за шкалою «прийняття інших». Емпірично визначено вікові особливості соціально-психологічної адаптації, а, саме, труднощі й переваги перебігу адаптаційних процесів представників юнацького та дорослого віку, що належать/не належать до неформальних субкультур. Достовірно найбільш дезадаптивними є пересічні юнаки, порівняно з пересічними дорослими чоловіками (р≤0,05) і хлопцями-неформалами (р≤0,01). В юнацькому віці кращі адаптаційні властивості в неформальному субкультурному середовищі виявили хлопці, порівняно з дорослими чоловіками, а в дорослому – жінки, порівняно з юними дівчатами. Здійснено статеву диференціацію особливостей перебігу адаптації в юнацькому та дорослому віці, з урахуванням впливу на цей процес неформальної субкультури. Виявлено негативну вікову динаміку інтегральної адаптації у представників чоловічої статі та позитивну – у представниць жіночої статі, які належать до неформальної субкультури. Загалом юнаки й дорослі жінки є більш адаптивними, порівняно з юнками і дорослими чоловіками. Доведено, що активні учасники неформальних груп соціально і психологічно краще адаптовані до цих груп, порівняно з адаптацією учасників формальних груп.

The association of developmental trajectories of adolescent mental health with early-adult functioning.

Mental health problems during adolescence may create a problematic start into adulthood for affected individuals. Usually, categorical indicators of adolescent mental health issues (yes/no psychiatric disorder) are used in studies into long-term functional outcomes. This however does not take into account the full spectrum of mental health, nor does it consider the trajectory of mental health problem development over time. The aim of this study was twofold: (1) to identify distinct developmental trajectories of (co-occurring) internalizing and externalizing mental health symptoms over the course of adolescence (ages 11-19), and (2) to document the associations between these adolescent trajectories and economic, social, and health outcomes in young adulthood (age 22), unadjusted and adjusted for childhood functioning, putative confounders and current mental health. Data were used from the Dutch TRAILS cohort study (subsample n = 1524, 47.3% males). Self-reported INT and EXT symptoms using the Youth/Adult Self Report were assessed four times (ages 11y, 13y, 16y, 19y). Adolescent mental health trajectories were estimated using Parallel-Processes Latent Class Growth Analyses. Self-reported economic, social, and health outcomes and parent-reported current mental health (using Adult Behaviour Checklist) were assessed at age 22. Multiple logistic regression analyses were performed to test associations between trajectories and outcomes. Four distinct trajectory classes were identified: (1) a normative class with decreasing-low INT+EXT symptoms (n = 460), (2) continuous moderately-high INT+EXT (n = 298), (3) continuous moderate, INT>EXT (n = 414), and (4) decreasing moderate, EXT>INT (n = 352). Compared to the normative class, the other three trajectories generally predicted less optimal early-adult outcomes, with the strongest effects observed for individuals with continuous moderate-high levels of both INT and EXT symptoms throughout adolescence. The associations largely remained after adjustment for pre-adolescent functioning, selected confounders and current mental health. Both adolescent trajectories and current mental health had substantial independent effects on early-adult functioning.

Developmental changes in parental authority legitimacy and over-time associations with adjustment: Differences in parent, first-born, and second-born perspectives.

Discrepancies in first- (M = 14.97 years, SD = 1.82) and second-born adolescents' (M = 12.20 years, SD = 1.90 years) and their parents' perceptions of parental authority legitimacy (PAL) were examined in a longitudinal sample of 145 predominantly White, middle-class, U.S. families. Utilizing a growth curve modeling approach, changes in the discrepancies between parents' and both first- and second-born adolescents' ratings of PAL over the course of 4 years were examined separately by the social-cognitive domain of the issues (social domain theory; Smetana, 2011; Turiel, 2002). We found that discrepancies between parents and first-borns increased over time for personal and multifaceted issues, whereas discrepancies for second-born adolescents increased over socially regulated issues. Additionally, larger initial discrepancies between parents and both adolescents over socially regulated issues (i.e., moral and conventional) were associated with greater depressive symptoms, while decreases in discrepancies over time were generally associated with better adjustment outcomes but with some domain and birth order differentiation. Discussion focuses on the developmental appropriateness (or inappropriateness) of family member perception differences in authority legitimacy over the course of adolescence. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cognitive Function Impairments Linked to Alcohol and Cannabis Use During Adolescence: A Study of Gender Differences.

Major neurocognitive changes occur during adolescence, making this phase one of the most critical developmental periods of life. Furthermore, this phase in life is also the time in which youth substance use begins. Several studies have demonstrated the differential associations of alcohol and cannabis use concerning the neurocognitive functioning of both males and females. Past and contemporary literature on gender-specific effects in neuroscience of addiction is predominantly based on cross-sectional datasets and data that is limited in terms of measurement variability. Given the importance of gender-specific effects in addiction studies, and in order to address the two above-mentioned gaps in the literature, the present study aimed to compare neurocognitive functioning of male and female adolescents in the context of cannabis and alcohol use, while employing a longitudinal design with multiple repeated measurements. Participants were 3,826 high school students (47% female; mean age, 12.7), who were recruited from 31 high schools in the greater Montreal area. Participants were requested to complete annual surveys for five consecutive years, from 7th to 11th grade, assessing their alcohol/cannabis use and neurocognitive functioning (working memory, delayed recall memory, perceptual reasoning, and inhibition control). The analytical strategy focused on the longitudinal association between each predictor (female, male) and each of the outcomes (domains of neurocognitive functioning). Multilevel linear models assessed the association of alcohol and cannabis consumption and the four domains of neurocognitive functioning. Results revealed a gender by within-subject interaction, suggesting a weaker effect of yearly fluctuation of cannabis use on working memory among males compared to females. Our findings suggest a different pattern of neurocognitive impairment of female and male working memory after using cannabis over the course of adolescence. Early initiation of cannabis use potentially results in more spatial working memory deficits in female adolescents. This may negatively influence young females’ capacity in academic settings and lead to significant impairment in adulthood, which critically decreases the individual’s quality of life.

Families and Relationships with Friends in the Genesis of Addiction in Adolescents. Essay on Life Course Analysis of 15–18 Year-Olds Enrolled in School, in Paris and the Surrounding Area (Ile-de-France)

Background Friends play an important role in cigarette and cannabis usage during adolescence. However, family is also a factor insofar as it can expose an adolescent to the development of consumption, or protect them from it. Experimentation with, and consumption of, these substances comes about within a specific relationship configuration: that of a somewhat conflictual relationship between young people and their parents. Methods The study was conducted in the Paris area (France) among 15–18-year-olds enrolled at school, with whom we conducted 93 biographical interviews (representing 483 person-years of retrospective observation). Results The consumption of cigarettes or cannabis is influenced by relationships with peers and meet-ups with friends (especially at weekends), as well as within the protective school environment. The relationship between adolescent consumption and parental attitude is two-way; consumption can be considered as much a cause of conflict as it is a consequence. Conclusions First, a product-based approach (tobacco or cannabis) is less fruitful than an approach of entry to addiction by life events. Secondly, analysis of both parent-adolescent conflicts and outings with friends seem to be powerful levers of action in preventing take-up of cigarettes and cannabis. Keypoints In the course of adolescence, behaviors in the consumption of cigarettes or cannabis connect with the relational context in which young people evolve at school community level The product-based approach (tobacco or cannabis) is less effective than an approach through analysis of both the conflicts and the nature of peer group meet-ups Analysis of parent-adolescent conflicts and control of meet-ups seem to be powerful levers of action for prevention of embarking on the use of products The Ageven grid for the description of life events is an innovative tool used to analyses a situation within the community as well as for the development of primary prevention

Developmental Trajectories of Sensorimotor and Cognitive Control in Gilles de la Tourette Syndrome

Abstract. The relationship between tics and preceding urges in Tourette syndrome suggests that abnormal internal monitoring is reflected in abnormal perceptual, attentional, and response selection. This article uses the theory of event coding to conceptualize Tourette syndrome as a disorder of the integration of perception and action. Given that Tourette syndrome is a prototypical neurodevelopmental disorder with a characteristic clinical course in childhood and early adolescence, we focus on reviewing developmental trajectories of perception-action binding and their neural correlates in Tourette and healthy controls with a view toward the dopaminergic system. Future cross-sectional and longitudinal research systematically comparing typical development and Tourette-related alterations of neurophysiological correlates underlying perception-action binding may shed light on individual differences in the clinical course in adolescence and adulthood.

Clinical cases of meningococcal infection caused by Neisseria meningitidis serogroup W

Meningococcal infection remains a socially significant disease due to a wide range of clinical manifestations, severe course with high mortality, reaching 40-80% for certain forms. In recent years we observe a change in the serogroup picture of meningococcal infection, in particular, an increase in the proportion of meningococcal serogroup W, characterized by polymorphism of clinical manifestations. The authors present two their own clinical observations of a generalized form of meningococcal infection with a severe course in adolescents caused by Neisseria meningitidis of W serogroup with fatal outcome. They describe the peculiarities of the cases, namely, inconsistency of the clinical picture at the beginning of the disease and post-mortem changes. The article describes heart damage in the form of focal purulent septic myocarditis and purulent foci of destruction in the brain stem, hemorrhagic infarction of the choroid plexus with hemotamponade of the lateral ventricles of the brain, the predominance of septicopia over septicemia. The revealed changes are likely to reflect clinical and morphological features of meningococcal infection caused by N. meningitidis of serogroup W.

Stress Exposure and the Course of ADHD from Childhood to Young Adulthood: Comorbid Severe Emotion Dysregulation or Mood and Anxiety Problems

Background: Compared to typically developing individuals, individuals with attention-deficit-hyperactivity disorder (ADHD) are on average more often exposed to stressful conditions (e.g., school failure, family conflicts, financial problems). We hypothesized that high exposure to stress relates to a more persistent and complex (i.e., multi-problem) form of ADHD, while low-stress exposure relates to remitting ADHD over the course of adolescence. Method: Longitudinal data (ages 11, 13, 16, and 19) came from the Tracking Adolescents’ Individual Life Survey (TRAILS). We selected children diagnosed with ADHD (n = 244; 167 males; 77 females) from the TRAILS clinical cohort and children who screened positive (n = 365; 250 males; 115 females) and negative (gender-matched: n = 1222; 831 males; 391 females) for ADHD from the TRAILS general population sample cohort (total n = 1587). Multivariate latent class growth analysis was applied to parent- and self-ratings of stress exposure, core ADHD problems (attention problems, hyperactivity/impulsivity), effortful control, emotion dysregulation (irritability, extreme reactivity, frustration), and internalizing problems (depression, anxiety, somatic complaints). Results: Seven distinct developmental courses in stress exposure and psychopathology were discerned, of which four related to ADHD. Two persistent ADHD courses of severely affected adolescents were associated with very high curvilinear stress exposure peaking in mid-adolescence: (1) Severe combined type with ongoing, severe emotional dysregulation, and (2) combined type with a high and increasing internalization of problems and elevated irritability; two partly remitting ADHD courses had low and declining stress exposure: (3) inattentive type, and (4) moderate combined type, both mostly without comorbid problems. Conclusions: High-stress exposure between childhood and young adulthood is strongly intertwined with a persistent course of ADHD and with comorbid problems taking the form of either severe and persistent emotion dysregulation (irritability, extreme reactivity, frustration) or elevated and increasing irritability, anxiety, and depression. Conversely, low and declining stress exposure is associated with remitting ADHD and decreasing internalizing and externalizing problems. Stress exposure is likely to be a facilitating and sustaining factor in these two persistent trajectories of ADHD with comorbid problems into young adulthood. Our findings suggest that a bidirectional, continuing, cycle of stressors leads to enhanced symptoms, in turn leading to more stressors, and so forth. Consideration of stressful conditions should, therefore, be an inherent part of the diagnosis and treatment of ADHD, to potentiate prevention and interruption of adverse trajectories.

White matter tract myelin maturation and its association with general psychopathology in adolescence and early adulthood.

Adolescence is a time period associated with marked brain maturation that coincides with an enhanced risk for onset of psychiatric disorder. White matter tract myelination, a process that continues to unfold throughout adolescence, is reported to be abnormal in several psychiatric disorders. Here, we ask whether psychiatric vulnerability is linked to aberrant developmental myelination trajectories. We assessed a marker of myelin maturation, using magnetisation transfer (MT) imaging, in 10 major white matter tracts. We then investigated its relationship to the expression of a general psychopathology “p‐factor” in a longitudinal analysis of 293 healthy participants between the ages of 14 and 24. We observed significant longitudinal MT increase across the full age spectrum in anterior thalamic radiation, hippocampal cingulum, dorsal cingulum and superior longitudinal fasciculus. MT increase in the inferior fronto‐occipital fasciculus, inferior longitudinal fasciculus and uncinate fasciculus was pronounced in younger participants but levelled off during the transition into young adulthood. Crucially, longitudinal MT increase in dorsal cingulum and uncinate fasciculus decelerated as a function of mean p‐factor scores over the study period. This suggests that an increased expression of psychopathology is closely linked to lower rates of myelin maturation in selective brain tracts over time. Impaired myelin growth in limbic association fibres may serve as a neural marker for emerging mental illness during the course of adolescence and early adulthood.

Effect of Cognitive Behavioral Therapy on Clinical Disease Course in Adolescents and Young Adults With Inflammatory Bowel Disease and Subclinical Anxiety and/or Depression: Results of a Randomized Trial.

Anxiety and depressive symptoms are prevalent in patients with inflammatory bowel disease (IBD) and may negatively influence disease course. Disease activity could be affected positively by treatment of psychological symptoms. We investigated the effect of cognitive behavioral therapy (CBT) on clinical disease course in 10-25-year-old IBD patients experiencing subclinical anxiety and/or depression. In this multicenter parallel group randomized controlled trial, IBD patients were randomized to disease-specific CBT in addition to standard medical care (CBT + care us usual [CAU]) or CAU only. The primary outcome was time to first relapse in the first 12 months. Secondary outcomes were clinical disease activity, fecal calprotectin, and C-reactive protein (CRP). Survival analyses and linear mixed models were performed to compare groups. Seventy patients were randomized (CBT+CAU = 37, CAU = 33), with a mean age of 18.3 years (±50% < 18 y, 31.4% male, 51.4% Crohn's disease, 93% in remission). Time to first relapse did not differ between patients in the CBT+CAU group vs the CAU group (n = 65, P = 0.915). Furthermore, clinical disease activity, fecal calprotectin, and CRP did not significantly change over time between/within both groups. Exploratory analyses in 10-18-year-old patients showed a 9% increase per month of fecal calprotectin and a 7% increase per month of serum CRP in the CAU group, which was not seen in the CAU+CBT group. CBT did not influence time to relapse in young IBD patients with subclinical anxiety and/or depression. However, exploratory analyses may suggest a beneficial effect of CBT on inflammatory markers in children.

Age-related differences in affective control and its association with mental health difficulties.

Difficulties in regulating affect are core characteristics of a wide range of mental health conditions and are associated with deficits in cognitive control, particularly in affective contexts, affective control. The current study explored how affective control relates to mental health over the course of adolescence. We developed an Affective Control Task, which was administered to young adolescents (11-14 years; n = 29); mid-adolescents (15-18 years; n = 31), and adults (22-30 years; n = 31). The task required individuals to sort cards according to continuously changing rules: color, number, or item type. There was a neutral condition in which items were shapes, and an affective condition, in which items were emotional facial expressions. Better affective control was associated with fewer mental health difficulties (p < .001, R2 = .15). Affective control partially accounted for the association between age group and mental health problems, z = 2.61, p = .009, Akaike information criterion = 484, with the association being strongest in young adolescents, r (27) = -.44, p = .018. Affective control further accounted for variance in the association between self-reported (but not experimental) emotion regulation and mental health (z = -3.44, p < .001, Akaike information criterion = 440). Poor affective control, especially in young adolescents, is associated with more mental health problems and higher levels of emotion regulation difficulties. Improving affective control therefore may constitute a promising target for prevention.

Beyond the Text Given: Studying the Scaffolding of Narrative Emotion Regulation as a Contribution to Bruner and Feldman's Cultural Cognitive Developmental Psychology.

Feldman et al. (Human Development, 36, 327-342, 1993) called for a new kind of psychology, a cultural cognitive developmental psychology. We critically consider their initial studies to discuss the scope of their program. In the spirit of this program we explore the development of scaffolding of narrative emotion regulation in adolescence. We present two co-narrations of sad events between mothers and their 12- and 18-year-old offspring to exemplify these mothers' age-sensitive strategies to scaffold adolescents' narrative emotion regulation. We identified three kinds of narrative arguments which mothers used for scaffolding and which are apparently acquired only in the course of adolescence: Embedding events in extended temporal, biographical contexts, relating events and reactions to individuals' enduring personalities, and re-appraising events by including more others', external, and hypothetical perspectives. They confirm developmental observations made by Feldman et al. (Human Development, 36, 327-342, 1993) and demonstrate their utility in the context of the development of emotion regulation.

P458 Effect of cognitive behavioural therapy on clinical disease course in adolescents and young adults with inflammatory bowel disease and subclinical anxiety and/or depression: results of a randomised trial

P458 Effect of cognitive behavioural therapy on clinical disease course in adolescents and young adults with inflammatory bowel disease and subclinical anxiety and/or depression: results of a randomised trial

98. How Low Can You Go? The Significance of Bradycardia For Acute Clinical Outcomes In Hospitalised Adolescents With Anorexia Nervosa

Bradycardia is one of the most prevalent physical symptoms in adolescents with anorexia nervosa (AN) and has been used as an indicator of physical severity that signals the need for hospital admission. Different clinical guidelines use different heart rate (HR) cut-points to guide admission, ranging from <50 to <40 beats per minute (bpm). These cut-points have been derived from expert consensus rather than evidence. This study aimed to understand the relationship between the severity of bradycardia and acute clinical course in adolescents with AN, with the broader goal of informing clinical practice. A retrospective cohort study was undertaken of adolescents with restrictive eating disorders admitted to a tertiary hospital specialist eating disorder program inpatient ward (May 2014 - Dec 2017). Adolescents with HR <50 bpm at admission were identified and categorised into 3 groups according to severity (mild, 45-49 bpm; moderate, 40-44 bpm; severe, <40 bpm). Clinical outcomes (eg metabolic, cardiovascular, length of stay) were analysed by severity group. Of the 393 admissions during the study period, 106 (27%) had HR <50 bpm at admission (mean [SD] age 15.3 [1.8] years, 83% female). Of these, the number of admissions with mild, moderate and severe bradycardia were 54, 42 and 10. Lower admission HR was associated with significantly longer duration of other measures of HR instability during admission. For example, the mean [SD] number of days with daytime HR<50 for those with mild, moderate and severe bradycardia was 4.22 [4.04], 5.38 [4.70] and 10.30 [5.07], respectively (p<0.001). More severe bradycardia was associated with longer hospital admission. For example, the mean length of stay for those with mild, moderate and moderate bradycardia was 14.4, 15.7 and 17.3 days. Admission HR can be used as an indicator of the severity and duration of HR instability during the course of admission. Applying different severity cut-points did not reveal significant differences in the frequency of other features of medical instability during admission, suggesting admission for bradycardia less than 50 bpm is appropriate. In this service, were the HR cut point for admission to be lowered, the number of admissions could be greatly reduced, but with a subsequent increased length of admission.

Development of working memory in the male adolescent rat

Working memory develops over the course of adolescence, and neuroimaging studies find development-associated changes in the activity of prefrontal cortical brain regions. Establishment of a rodent model of working memory development would permit more comprehensive studies of the molecular and circuit basis for working memory development in health and disease. Thus, in this study, working memory performance was compared between adolescent and adult male Sprague-Dawley rats using an operant-based, delay-match-to-sample working memory task. Adolescent and adult rats showed similar rates of learning the task and similar performance at a low cognitive load (delays ≤ 6 s). However, when the cognitive load increased, adolescents exhibited impaired working memory performance relative to adults, until postnatal day 50 when performance was not significantly different. Despite evidence that cannabinoids disrupt working memory, we found no effect of acute treatment with the cannabinoid receptor agonist, WIN55212,2, at either age. Moreover, expression of glutamate and GABA receptor subunits was examined in the prelimbic and infralimbic prefrontal cortex across development. NMDA receptor subunit GluN2B expression significantly decreased with age in parallel with improvements in working memory. Thus, we show evidence that rats can be used as a model to study the molecular underpinnings of working memory development.