In Context: Lessons About Adolescent Unipolar Depression From the Improving Mood With Psychoanalytic and Cognitive Therapies Trial.

This paper summarizes the results of the Improving Mood with Psychoanalytic and Cognitive Therapies (IMPACT) study and its implications for psychological treatment of adolescents with moderate to severe unipolar major depression. IMPACT was a pragmatic, superiority, randomized controlled trial conducted in the United Kingdom, which compared the clinical and cost-effectiveness of short-term psychoanalytic therapy (STPP), cognitive-behavioral therapy (CBT), and a brief psychosocial intervention (BPI) in reducing depression symptoms in 465 adolescents with unipolar major depression, aged 11 to 17 years. Although this was a clinically heterogeneous group of adolescents, some symptoms (eg, sleep and concentration difficulties, irritability/anger) were common and disabling. The trial reported no significant difference among the 3 treatments in reducing depression symptoms. One year after treatment, 84% of participants showed improvement in depressive symptoms (<50% of baseline symptoms) and improved psychosocial functioning, achieving this through different symptom reduction trajectories. Although participants attended fewer treatment sessions than planned, the 3 treatments were delivered with fidelity to their respective models. Ending treatment without therapist agreement occurred in 37% of cases. This was not associated with outcomes by treatment group. Adolescents emphasized the importance of the therapeutic relationship in all 3 treatments. Results suggest that although most adolescents respond to time-limited, structured psychological therapy, subgroups of depressed adolescents are likely to need additional treatment or support. These include adolescents who live in complex circumstances and/or who believe that their needs are not met in therapy, some who stop treatment early, and the 16% to 18% of adolescents who do not respond to treatment. CLINICAL TRIAL REGISTRATION INFORMATION: Improving Mood and Preventing Relapse With Psychoanalytic Psychotherapy and Cognitive Behaviour Therapy; https://www.isrctn.com; ISRCTN83033550.

Self-reported childhood family adversity is linked to an attenuated gain of trust during adolescence.

A longstanding proposal in developmental research is that childhood family experiences provide a template that shapes a capacity for trust-based social relationships. We leveraged longitudinal data from a cohort of healthy adolescents (n = 570, aged 14-25), which included decision-making and psychometric data, to characterise normative developmental trajectories of trust behaviour and inter-individual differences therein. Extending on previous cross-sectional findings from the same cohort, we show that a task-based measure of trust increases longitudinally from adolescence into young adulthood. Computational modelling suggests this is due to a decrease in social risk aversion. Self-reported family adversity attenuates this developmental gain in trust behaviour, and within our computational model, this relates to a higher 'irritability' parameter in those reporting greater adversity. Unconditional trust at measurement time point T1 predicts the longitudinal trajectory of self-reported peer relation quality, particularly so for those with higher family adversity, consistent with trust acting as a resilience factor.

Measurement Invariance in Longitudinal Bifactor Models: Review and Application Based on the p Factor.

Bifactor models are increasingly being utilized to study latent constructs such as psychopathology and cognition, which change over the lifespan. Although longitudinal measurement invariance (MI) testing helps ensure valid interpretation of change in a construct over time, this is rarely and inconsistently performed in bifactor models. Our review of MI simulation literature revealed that only one study assessed MI in bifactor models under limited conditions. Recommendations for how to assess MI in bifactor models are suggested based on existing simulation studies of related models. Estimator choice and influence of missing data on MI are also discussed. An empirical example based on a model of the general psychopathology factor (p) elucidates our recommendations, with the present model of p being the first to exhibit residual MI across gender and time. Thus, changes in the ordered-categorical indicators can be attributed to changes in the latent factors. However, further work is needed to clarify MI guidelines for bifactor models, including considering the impact of model complexity and number of indicators. Nonetheless, using the guidelines justified herein to establish MI allows findings from bifactor models to be more confidently interpreted, increasing their comparability and utility.

Research Review: Integrated healthcare for children and young people in secondary/tertiary care - a systematic review.

BACKGROUND: Children and young people (CYP) with comorbid physical and/or mental health conditions often struggle to receive a timely diagnosis, access specialist mental health care, and more likely to report unmet healthcare needs. Integrated healthcare is an increasingly explored model to support timely access, quality of care and better outcomes for CYP with comorbid conditions. Yet, studies evaluating the effectiveness of integrated care for paediatric populations are scarce. AIM AND METHODS: This systematic review synthesises and evaluates the evidence for effectiveness and cost-effectiveness of integrated care for CYP in secondary and tertiary healthcare settings. Studies were identified through systematic searches of electronic databases: Medline, Embase, PsychINFO, Child Development and Adolescent Studies, ERIC, ASSIA and British Education Index. FINDINGS: A total of 77 papers describing 67 unique studies met inclusion criteria. The findings suggest that integrated care models, particularly system of care and care coordination, improve access and user experience of care. The results on improving clinical outcomes and acute resource utilisation are mixed, largely due to the heterogeneity of studied interventions and outcome measures used. No definitive conclusion can be drawn on cost-effectiveness since studies focused mainly on costs of service delivery. The majority of studies were rated as weak by the quality appraisal tool used. CONCLUSIONS: The evidence of on clinical effectiveness of integrated healthcare models for paediatric populations is limited and of moderate quality. Available evidence is tentatively encouraging, particularly in regard to access and user experience of care. Given the lack of specificity by medical groups, however, the precise model of integration should be undertaken on a best-practice basis taking the specific parameters and contexts of the health and care environment into account. Agreed practical definitions of integrated care and associated key terms, and cost-effectiveness evaluations are a priority for future research.

Shorter sleep among adolescents is associated with lower fruit and vegetable consumption the following day.

BACKGROUND: Insufficient sleep has been associated with weight gain and metabolic dysregulation, with one suggested mechanism being through reduction in diet quality. Experimental evidence supports a causal effect of sleep timings on diet but this may not be applicable to a free-living adolescent population. In this analysis we use daily measures of sleep timings and diet quality, to examine the effect of sleep duration and timing on diet quality the following day among free-living adolescents. METHODS: The ROOTS study is a prospective cohort recruited from secondary schools in Cambridgeshire and Suffolk (UK). Participants (n = 815) at mean age 15.0y (SD 0.3y) completed a diet diary and wore a combined heart rate and accelerometer device over 4 consecutive days. Sleep duration and timing (midpoint) were derived from acceleration and heart rate traces, while daily energy density and fruit and vegetable intake were calculated from dietary data. Analyses were performed at day-level (1815 person-days). Multilevel random effects models were used to test associations between sleep each night and subsequent day diet, with daily sleep and diet measures nested within individuals and schools, and adjusted for day-level and individual-level confounding variables. RESULTS: Adolescents slept a mean of 7.88 hrs (SD 1.10) per night, reporting a mean energy density of 2.12 kcal/g (SD 0.48) and median energy-adjusted daily fruit and vegetable intake of 137.3 g (IQR 130.4). One hour shorter sleep duration was associated with lower intake of fruit and vegetables (-6.42 g, 95%CI -1.84, -10.99) the following day. An association with higher dietary energy density (0.016 kcal/g, 95%CI 0.034, -0.002) the following day was observed but did not reach statistical significance. Sleep timing was not associated with either fruit and vegetable intake (-2.52 g/d, 95%CI -7.66, 2.62) or dietary energy density (-0.001 kcal/g, 95%CI -0.022, 0.020). CONCLUSIONS: Our observational findings from a free-living adolescent population support the experimental evidence for a causal role of sleep on diet, with shorter sleep duration at night leading to a small decrease in diet quality the following day. These findings support experimental evidence to suggest inclusion of sleep duration as one component of interventions designed to improve diet quality and weight status in adolescents.

Action selection in early stages of psychosis: an active inference approach.

BACKGROUND: To interact successfully with their environment, humans need to build a model to make sense of noisy and ambiguous inputs. An inaccurate model, as suggested to be the case for people with psychosis, disturbs optimal action selection. Recent computational models, such as active inference, have emphasized the importance of action selection, treating it as a key part of the inferential process. Based on an active inference framework, we sought to evaluate previous knowledge and belief precision in an action-based task, given that alterations in these parameters have been linked to the development of psychotic symptoms. We further sought to determine whether task performance and modelling parameters would be suitable for classification of patients and controls. METHODS: Twenty-three individuals with an at-risk mental state, 26 patients with first-episode psychosis and 31 controls completed a probabilistic task in which action choice (go/no-go) was dissociated from outcome valence (gain or loss). We evaluated group differences in performance and active inference model parameters and performed receiver operating characteristic (ROC) analyses to assess group classification. RESULTS: We found reduced overall performance in patients with psychosis. Active inference modelling revealed that patients showed increased forgetting, reduced confidence in policy selection and less optimal general choice behaviour, with poorer action-state associations. Importantly, ROC analysis showed fair-to-good classification performance for all groups, when combining modelling parameters and performance measures. LIMITATIONS: The sample size is moderate. CONCLUSION: Active inference modelling of this task provides further explanation for dysfunctional mechanisms underlying decision-making in psychosis and may be relevant for future research on the development of biomarkers for early identification of psychosis.

Stratification of adolescents across mental phenomena emphasizes the importance of transdiagnostic distress: a replication in two general population cohorts.

Characterizing patterns of mental phenomena in epidemiological studies of adolescents can provide insight into the latent organization of psychiatric disorders. This avoids the biases of chronicity and selection inherent in clinical samples, guides models of shared aetiology within psychiatric disorders and informs the development and implementation of interventions. We applied Gaussian mixture modelling to measures of mental phenomena from two general population cohorts: the Avon Longitudinal Study of Parents and Children (ALSPAC, n = 3018) and the Neuroscience in Psychiatry Network (NSPN, n = 2023). We defined classes according to their patterns of both positive (e.g. wellbeing and self-esteem) and negative (e.g. depression, anxiety, and psychotic experiences) phenomena. Subsequently, we characterized classes by considering the distribution of diagnoses and sex split across classes. Four well-separated classes were identified within each cohort. Classes primarily differed by overall severity of transdiagnostic distress rather than particular patterns of phenomena akin to diagnoses. Further, as overall severity of distress increased, so did within-class variability, the proportion of individuals with operational psychiatric diagnoses. These results suggest that classes of mental phenomena in the general population of adolescents may not be the same as those found in clinical samples. Classes differentiated only by overall severity support the existence of a general, transdiagnostic mental distress factor and have important implications for intervention.

Why Is Non-suicidal Self-injury More Common in Women? Mediation and Moderation Analyses of Psychological Distress, Emotion Dysregulation, and Impulsivity.

OBJECTIVE: Non-suicidal self-injury (NSSI) appears to be more common among women than men, though the underlying reasons for this remain unclear. In a community sample of young adults (N = 996, aged 18-33) assessed during the COVID-19 pandemic, we investigated alternative explanation for the NSSI prevalence gap: are women more likely to experience the feelings which lead to NSSI as a coping strategy, or does this prevalence gap result from differences in how men and women respond to distress? METHODS: Cross-sectional mediation and moderation analyses tested how self-reported psychological distress (K10), emotion dysregulation (DERS), and impulsivity (UPPS-P) may contribute to a higher prevalence of NSSI among women. RESULTS: Women were twice as likely as men to report past-year NSSI (14.47% versus 7.78%, OR = 2.00, 95% CI [1.29, 3.13]). Women reported significantly higher psychological distress and significantly lower sensation seeking and positive urgency than men. Psychological distress partially statistically mediated the relationship between gender and past-year NSSI. Gender did not significantly moderate associations between psychological distress, emotion dysregulation, or impulsivity and past-year NSSI. Past-year NSSI prevalence did not significantly decrease with age and we found no significant age by gender interaction. CONCLUSIONS: Greater levels of NSSI in young women are partly explained by their greater levels of psychological distress, but not by differences in how men and women respond to this distress. Given similar levels of psychological distress, emotion dysregulation, and impulsivity, women and men are similarly likely to experience NSSI. HighlightsWomen aged 18-33 were significantly more likely to report past-year NSSI than menWomen's greater psychological distress contributed to their higher NSSI prevalenceVariables investigated here were similarly associated with NSSI in men and women.

Elevated cognitive rumination and adverse life events are associated with lower cortical surface area and suicidal ideation in adolescents with major depressive disorder.

INTRODUCTION: Suicide is the second most common cause of death among young people. Structural brain alterations, rumination, and recent stressful experiences contribute to suicidal thoughts and behaviors (STBs). METHODS: Here, we employed structural equation modeling (SEM) to examine the unique and combined relationships of these risk factors with STBs in a sample of young people with major depressive disorder (MDD) from the Magnetic Resonance-Improving Mood with Psychoanalytic and Cognitive Therapies (MR-IMPACT) study (N = 67, mean age = 15.90; standard deviation ± 1.32). RESULTS: Whereas increased rumination and lower surface area of brain regions, that have been previously reported to be involved in both STBs and rumination, were associated with each other (Beta = -0.268, standard error (SE) = 0.114, Z = -2.346, p = 0.019), only increased rumination was related to greater severity of suicidal ideation (Beta = 0.281, SE = 0.132, Z = 2.134, p = 0.033). In addition, we observed that recent stress was associated with lower surface area in the suicidal ideation model without covariate only (Beta = -0.312, SE = 0.149, Z = -2.089, p = 0.037). For the attempt models, no associations were found between any of the risk factors and suicide attempts. LIMITATIONS: We emphasize that these findings from this secondary analysis are hypothesis-forming and preliminary in nature given the small sample size for SEM analyses. CONCLUSION: Our findings suggest that neither lower surface area nor recent stress are directly associated with youth suicidal ideation or attempt. However, lower surface area is related to recent stress and increased rumination, which predicted greater severity of suicidal ideation in young people with MDD.

The impact of the initial COVID-19 outbreak on young adults' mental health: a longitudinal study of risk and resilience factors.

Few studies assessing the effects of COVID-19 on mental health include prospective markers of risk and resilience necessary to understand and mitigate the combined impacts of the pandemic, lockdowns, and other societal responses. This population-based study of young adults includes individuals from the Neuroscience in Psychiatry Network (n = 2403) recruited from English primary care services and schools in 2012-2013 when aged 14-24. Participants were followed up three times thereafter, most recently during the initial outbreak of the COVID-19 outbreak when they were aged between 19 and 34. Repeated measures of psychological distress (K6) and mental wellbeing (SWEMWBS) were supplemented at the latest assessment by clinical measures of depression (PHQ-9) and anxiety (GAD-7). A total of 1000 participants, 42% of the original cohort, returned to take part in the COVID-19 follow-up; 737 completed all four assessments [mean age (SD), 25.6 (3.2) years; 65.4% female; 79.1% White]. Our findings show that the pandemic led to pronounced deviations from existing mental health-related trajectories compared to expected levels over approximately seven years. About three-in-ten young adults reported clinically significant depression (28.8%) or anxiety (27.6%) under current NHS guidelines; two-in-ten met clinical cut-offs for both. About 9% reported levels of psychological distress likely to be associated with serious functional impairments that substantially interfere with major life activities; an increase by 3% compared to pre-pandemic levels. Deviations from personal trajectories were not necessarily restricted to conventional risk factors; however, individuals with pre-existing health conditions suffered disproportionately during the initial outbreak of the COVID-19 pandemic. Resilience factors known to support mental health, particularly in response to adverse events, were at best mildly protective of individual psychological responses to the pandemic. Our findings underline the importance of monitoring the long-term effects of the ongoing pandemic on young adults' mental health, an age group at particular risk for the emergence of psychopathologies. Our findings further suggest that maintaining access to mental health care services during future waves, or potential new pandemics, is particularly crucial for those with pre-existing health conditions. Even though resilience factors known to support mental health were only mildly protective during the initial outbreak of the COVID-19 pandemic, it remains to be seen whether these factors facilitate mental health in the long term.

Sexually divergent development of depression-related brain networks during healthy human adolescence.

Sexual differences in human brain development could be relevant to sex differences in the incidence of depression during adolescence. We tested for sex differences in parameters of normative brain network development using fMRI data on N = 298 healthy adolescents, aged 14 to 26 years, each scanned one to three times. Sexually divergent development of functional connectivity was located in the default mode network, limbic cortex, and subcortical nuclei. Females had a more "disruptive" pattern of development, where weak functional connectivity at age 14 became stronger during adolescence. This fMRI-derived map of sexually divergent brain network development was robustly colocated with i prior loci of reward-related brain activation ii a map of functional dysconnectivity in major depressive disorder (MDD), and iii an adult brain gene transcriptional pattern enriched for genes on the X chromosome, neurodevelopmental genes, and risk genes for MDD. We found normative sexual divergence in adolescent development of a cortico-subcortical brain functional network that is relevant to depression.

Device-measured sleep onset and duration in the development of depressive symptoms in adolescence.

BACKGROUND: Sleep deprivation in adolescence is increasing in prevalence and may be linked to subsequent depression. Findings regarding associations between sleep duration, sleep onset time, and the development of depressive symptoms over time in adolescents are mixed, and rely on subjective measures of sleep. METHODS: Sleep onset and duration were assessed using a combined heart rate monitor and accelerometer and self-report in 688 participants from the ROOTS study at age 15. Participants reported depressive symptoms at ages 14.5, 16, and 17.5, using the Mood and Feelings Questionnaire. Latent growth curve modelling was used to model development of depressive symptoms and test associations with baseline sleep onset and duration. RESULTS: Cross-sectionally, falling asleep later and shorter sleep duration were both associated with higher depressive symptoms in males and females, using both device-measured and self-reported sleep. There were no longitudinal associations between baseline sleep duration and change in depressive symptoms. A later sleep onset-time was associated with a decrease in depressive symptoms over time, in females only, using device-measured sleep only. LIMITATIONS: The current sample was more economically advantaged and ethnically white than the UK average, and with lower MFQ symptoms than the original cohort, which may reduce generalisability. CONCLUSIONS: Adolescents who fall asleep later or sleep less have higher levels of depressive symptoms cross-sectionally, but do not show increases in depressive symptoms over time. Interventions targeting sleep onset and duration in adolescence may improve mental health in the short-term but the possibility of reverse causality should be explored further.

Associations between COVID-19 pandemic impact, dimensions of behavior and eating disorders: A longitudinal UK-based study.

BACKGROUND: There is growing concern about how people with eating disorders are impacted by the widespread societal restructuring during the COVID-19 crisis. AIMS: We aimed to examine how factors relating to the impact of the pandemic associate with eating disorders and quantify this relationship while adjusting for concurrent and longitudinal parameters of risk. METHODS: We gathered demographic, behavioral and clinical data pre- and mid-pandemic as well as childhood trauma history from a longitudinal online survey of 489 adults (mean age 23.4 years) recruited from the Neuroscience in Psychiatry Network (NSPN). Using pre-pandemic (T1) and concurrent (T2) data we aimed to predict eating disorders at mid-pandemic (T2). We deployed hierarchical generalized logistic regression to ascertain the strength of longitudinal and concurrent associations. RESULTS: Pre-pandemic eating disorder scores strongly associated with concurrent eating disorder (z = 5.93). More conflict at home mid-pandemic (z = 2.03), pre- (lower sensation seeking z = -2.58) and mid-pandemic (higher lack of perseverance z = 2.33) impulsivity traits also associated with mid-pandemic eating disorder. CONCLUSION: Conflict at home mid-pandemic and specific aspects of impulsiveness significantly associated with concurrent eating disorder when adjusted for pre-pandemic eating disorder symptoms, baseline demographics, behavioral traits, history of traumatic experiences and concurrent psychopathology. These results provide insight into the struggles of those suffering with eating disorders during the COVID-19 pandemic and highlight the importance of impulsiveness traits and the immediate family environment in their experience of illness during the pandemic.

Cross-sectional and longitudinal associations between psychotic and depressive symptoms in depressed adolescents.

Adults with major depressive disorder (MDD) with psychotic features (delusions and/or hallucinations) have more severe symptoms and a worse prognosis. Subclinical psychotic symptoms are more common in adolescents than adults. However, the effects of psychotic symptoms on outcome of depressive symptoms have not been well studied in adolescents. Depressed adolescents aged 11-17 with and without psychotic symptoms were compared on depression severity scores at baseline and at 28- or 42-week follow-up in two large UK cohorts. Psychotic symptoms were weakly associated with more severe depression at baseline in both cohorts. At follow-up, baseline psychotic symptoms were only associated with depressive symptoms in one sample; in the other, the effect size was close to zero. This supports the DSM5 system of psychotic symptoms being a separate code to severity rather than the ICD10 system which only allows the diagnosis of psychotic depression with severe depression. There was no clear support for psychotic symptoms being a baseline marker of treatment response.

Brain grey and white matter structural associations with future suicidal ideation and behaviors in adolescent and young adult females with mood disorders.

Background: To reduce suicide in females with mood disorders, it is critical to understand brain substrates underlying their vulnerability to future suicidal ideation and behaviors (SIBs) in adolescence and young adulthood. In an international collaboration, grey and white matter structure was investigated in adolescent and young adult females with future suicidal behaviors (fSB) and ideation (fSI), and without SIBs (fnonSIB). Methods: Structural (n = 91) and diffusion-weighted (n = 88) magnetic resonance imaging scans at baseline and SIB measures at follow-up on average two years later (standard deviation, SD = 1 year) were assessed in 92 females [age(SD) = 16.1(2.6) years] with bipolar disorder (BD, 28.3%) or major depressive disorder (MDD, 71.7%). One-way analyses of covariance comparing baseline regional grey matter cortical surface area, thickness, subcortical grey volumes, or white matter tensor-based fractional anisotropy across fSB (n = 40, 43.5%), fSI (n = 33, 35.9%) and fnonSIB (n = 19, 20.6%) groups were followed by pairwise comparisons in significant regions (p < 0.05). Results: Compared to fnonSIBs, fSIs and fSBs showed significant decreases in cortical thickness of right inferior frontal gyrus pars orbitalis and middle temporal gyrus, fSIs of left inferior frontal gyrus, pars orbitalis. FSIs and fSBs showed lower fractional anisotropy in left uncinate fasciculus and corona radiata, and fSBs in right uncinate and superior fronto-occipital fasciculi. Conclusions: The study provides preliminary evidence of grey and white matter alterations in brain regions subserving emotional and behavioral regulation and perceptual processing in adolescent and young adult females with mood disorders with, versus without, future SIBs. Findings suggest potential targets to prevent SIBs in female adolescents and young adults.

Behavioral measures of impulsivity and compulsivity in adolescents with nonsuicidal self-injury.

BACKGROUND: Nonsuicidal self-injury (NSSI) is prevalent among adolescents and research is needed to clarify the mechanisms which contribute to the behavior. Here, the authors relate behavioral neurocognitive measures of impulsivity and compulsivity to repetitive and sporadic NSSI in a community sample of adolescents. METHODS: Computerized laboratory tasks (Affective Go/No-Go, Cambridge Gambling Task, and Probabilistic Reversal Task) were used to evaluate cognitive performance. Participants were adolescents aged 15 to 17 with (n = 50) and without (n = 190) NSSI history, sampled from the ROOTS project which recruited adolescents from secondary schools in Cambridgeshire, UK. NSSI was categorized as sporadic (1-3 instances per year) or repetitive (4 or more instances per year). Analyses were carried out in a series of linear and negative binomial regressions, controlling for age, gender, intelligence, and recent depressive symptoms. RESULTS: Adolescents with lifetime NSSI, and repetitive NSSI specifically, made significantly more perseverative errors on the Probabilistic Reversal Task and exhibited significantly lower quality of decision making on the Cambridge Gambling Task compared to no-NSSI controls. Those with sporadic NSSI did not significantly differ from no-NSSI controls on task performance. NSSI was not associated with behavioral measures of impulsivity. CONCLUSIONS: Repetitive NSSI is associated with increased behavioral compulsivity and disadvantageous decision making, but not with behavioral impulsivity. Future research should continue to investigate how neurocognitive phenotypes contribute to the onset and maintenance of NSSI, and determine whether compulsivity and addictive features of NSSI are potential targets for treatment.

Hopelessness and depressive symptoms in children and adolescents: An integrative data analysis.

Although hopelessness has been linked to depression for centuries, the diagnostic criteria for depression are inconsistent with regard to the status of hopelessness. Most research on hopelessness and depression has focused on adults. The current study examined this relation in children and adolescents. Integrative data analyses with a pooled sample (N = 2466) showed that clinical levels of hopelessness multiplied the odds of having a clinical diagnosis of depression 10-fold. Conversely, not having clinical levels of hopelessness multiplied the odds of endorsing no clinical level of depressive symptoms 28-fold. Moreover, results differed by levels of depression: (a) among youths with clinical levels of depression, hopelessness was associated with six depressive symptoms; (b) among youths without clinical levels of depression, hopelessness was associated with nine depressive symptoms. We found that hopelessness helps to explain the heterogeneity of depressive presentations. Our finding supports the consideration of hopelessness in the diagnosis (if not treatment and prevention) of depression in children and adolescents. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Preference uncertainty accounts for developmental effects on susceptibility to peer influence in adolescence.

Adolescents are prone to social influence from peers, with implications for development, both adaptive and maladaptive. Here, using a computer-based paradigm, we replicate a cross-sectional effect of more susceptibility to peer influence in a large dataset of adolescents 14 to 24 years old. Crucially, we extend this finding by adopting a longitudinal perspective, showing that a within-person susceptibility to social influence decreases over a 1.5 year follow-up time period. Exploiting this longitudinal design, we show that susceptibility to social influences at baseline predicts an improvement in peer relations over the follow-up period. Using a Bayesian computational model, we demonstrate that in younger adolescents a greater tendency to adopt others' preferences arises out of a higher uncertainty about their own preferences in the paradigmatic case of delay discounting (a phenomenon called 'preference uncertainty'). This preference uncertainty decreases over time and, in turn, leads to a reduced susceptibility of one's own behaviour to an influence from others. Neuro-developmentally, we show that a measure of myelination within medial prefrontal cortex, estimated at baseline, predicts a developmental decrease in preference uncertainty at follow-up. Thus, using computational and neural evidence, we reveal adaptive mechanisms underpinning susceptibility to social influence during adolescence.

Brain micro-architecture and disinhibition: a latent phenotyping study across 33 impulsive and compulsive behaviours.

Impulsive and compulsive symptoms are common, tend to co-occur, and collectively account for a substantive global disease burden. Latent phenotyping offers a promising approach to elucidate common neural mechanisms conferring vulnerability to such symptoms in the general population. We utilised the Neuroscience in Psychiatry Network (NSPN), a cohort of young people (aged 18-29 years) in the United Kingdom, who provided questionnaire data and Magnetic Resonance Imaging scans. Partial Least Squares was used to identify brain regions in which intra-cortical myelination (measured using Magnetisation Transfer, MT) was significantly associated with a disinhibition phenotype, derived from bi-factor modelling of 33 impulsive and compulsive problem behaviours. The neuroimaging sample comprised 126 participants, mean 22.8 (2.7 SD) years old, being 61.1% female. Disinhibition scores were significantly and positively associated with higher MT in the bilateral frontal and parietal lobes. 1279 genes associated with disinhibition-related brain regions were identified, which were significantly enriched for functional biological interactions reflecting receptor signalling pathways. This study indicates common microstructural brain abnormalities contributing to a multitude of related, prevalent, problem behaviours characterised by disinhibition. Such a latent phenotyping approach provides insights into common neurobiological pathways, which may help to improve disease models and treatment approaches. Now that this latent phenotyping model has been validated in a general population sample, it can be extended into patient settings.

Influence of prior beliefs on perception in early psychosis: Effects of illness stage and hierarchical level of belief.

Alterations in the balance between prior expectations and sensory evidence may account for faulty perceptions and inferences leading to psychosis. However, uncertainties remain about the nature of altered prior expectations and the degree to which they vary with the emergence of psychosis. We explored how expectations arising at two different levels-cognitive and perceptual-influenced processing of sensory information and whether relative influences of higher- and lower-level priors differed across people with prodromal symptoms and those with psychotic illness. In two complementary auditory perception experiments, 91 participants (30 with first-episode psychosis, 29 at clinical risk for psychosis, and 32 controls) were required to decipher a phoneme within ambiguous auditory input. Expectations were generated in two ways: an accompanying visual input of lip movements observed during auditory presentation or through written presentation of a phoneme provided prior to auditory presentation. We determined how these different types of information shaped auditory perceptual experience, how this was altered across the prodromal and established phases of psychosis, and how this relates to cingulate glutamate levels assessed by magnetic resonance spectroscopy. The psychosis group relied more on high-level cognitive priors compared to both healthy controls and those at clinical risk for psychosis and relied more on low-level perceptual priors than the clinical risk group. The risk group was marginally less reliant on low-level perceptual priors than controls. The results are consistent with previous theory that influences of prior expectations in perceptions in psychosis differ according to level of prior and illness phase. (PsycInfo Database Record (c) 2020 APA, all rights reserved).