Mediterranean Diet and Mental Health in Children and Adolescents: A Systematic Review.

CONTEXT: Childhood and adolescence are periods of critical importance in the development of mental health disorders. The Mediterranean diet (MD) has been linked to multiple positive health outcomes, including reduced incidence of mental health disorders and fewer psychiatric symptoms. OBJECTIVE: This study aimed to investigate the association between adherence to an MD and mental health outcomes in children and adolescents. METHODS: A systematic literature review was conducted of original research that explored the relationship between psychiatric symptoms or disorders and adherence to an MD. The literature search was conducted on PubMed, Scopus, Web of Science, MEDES, Dialnet, and Latindex from inception to November 2022, and the Newcastle-Ottawa Scale was used to evaluate the quality of studies. RESULTS: A total of 13 studies (6 cross-sectional, 4 case-control, 2 randomized clinical trials, and 1 longitudinal cohort) out of 450 met the inclusion criteria. A total of 3058 children or adolescents with a mean age range from 8.6 to 16.2 years were included. Among the reviewed studies, 5 (71.42%) of those looking at attention-deficit/hyperactivity disorder, 4 (80%) examining depression, and 2 (50%) assessing anxiety found a significant protective association. Seven articles (53.84%) were found to be of high quality and 6 (46.15%) of moderate quality. CONCLUSION: Adherence to an MD could be a protective factor for mental health in child and adolescent populations. This suggests that promoting an MD could help prevent the onset of clinical psychiatric symptoms, reduce symptom severity, and improve prognosis in young patients. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021276316.

Running in the FAMILY: understanding and predicting the intergenerational transmission of mental illness.

Over 50% of children with a parent with severe mental illness will develop mental illness by early adulthood. However, intergenerational transmission of risk for mental illness in one's children is insufficiently considered in clinical practice, nor is it sufficiently utilised into diagnostics and care for children of ill parents. This leads to delays in diagnosing young offspring and missed opportunities for protective actions and resilience strengthening. Prior twin, family, and adoption studies suggest that the aetiology of mental illness is governed by a complex interplay of genetic and environmental factors, potentially mediated by changes in epigenetic programming and brain development. However, how these factors ultimately materialise into mental disorders remains unclear. Here, we present the FAMILY consortium, an interdisciplinary, multimodal (e.g., (epi)genetics, neuroimaging, environment, behaviour), multilevel (e.g., individual-level, family-level), and multisite study funded by a European Union Horizon-Staying-Healthy-2021 grant. FAMILY focuses on understanding and prediction of intergenerational transmission of mental illness, using genetically informed causal inference, multimodal normative prediction, and animal modelling. Moreover, FAMILY applies methods from social sciences to map social and ethical consequences of risk prediction to prepare clinical practice for future implementation. FAMILY aims to deliver: (i) new discoveries clarifying the aetiology of mental illness and the process of resilience, thereby providing new targets for prevention and intervention studies; (ii) a risk prediction model within a normative modelling framework to predict who is at risk for developing mental illness; and (iii) insight into social and ethical issues related to risk prediction to inform clinical guidelines.

Clinical and neurodevelopmental predictors of psychotic disorders in children and adolescents at clinical high risk for psychosis: the CAPRIS study.

BACKGROUND: The neurodevelopmental hypothesis of schizophrenia represents the disorder as an expression of an alteration during the brain development process early in life. Neurodevelopmental variables could become a trait marker, and the study of these variables in children and adolescents at clinical high risk for psychosis (CHR) could identify a specific cluster of patients who later developed psychosis. The aim of this study is to describe clinical and neurodevelopment predictors of transition to psychosis in child and adolescent participants at CHR. Naturalistic longitudinal two-center study of 101 CHR and 110 healthy controls (HC) aged 10-17. CHR participants were children and adolescents aged 10-17, meeting one or more of the CHR criteria assessed at baseline and at 18 months' follow-up. Neurodevelopmental variables assessed were obstetric complications, delay in principal development milestones, and presence of a neurodevelopment diagnosis. Pairwise comparisons, linear regressions, and binary logistic regression were performed.A transition rate of 23.3% at 1.5 years was observed. Participants who developed psychosis (CHR-P) showed higher rates of grandiosity and higher proportions of antipsychotic medication intake at baseline compared to participants who did not develop a psychotic disorder (CHR-NP). In terms of neurodevelopment alterations, CHR-P group showed a higher proportion of participants reporting delay in language development than the CHR-NP and HC groups. The odds of psychosis increased by 6.238 CI 95% [1.276-30.492] for a one-unit increase in having a positive score in grandiosity; they increased by 4.257 95% CI [1.293-14.023] for a one-unit increase in taking antipsychotic medication, and by 4.522 95% [1.185-64.180] for showing language development delay. However, the p-values did not reach significance after adjusting for multiple comparisons.A combination of clinical and neurodevelopmental alterations could help predict the transition to psychotic disorder in a CHR child and adolescent sample. Our results suggest the potential utility of collecting information about neurodevelopment and using these variable multifactorial models to predict psychosis disorders.

Polygenic risk scores mediating functioning outcomes through cognitive and clinical features in youth at family risk and controls.

Schizophrenia and bipolar disorder exhibit substantial clinical overlap, particularly in individuals at familial high risk, who frequently present sub-threshold symptoms before the onset of illness. Severe mental disorders are highly polygenic traits, but their impact on the stages preceding the manifestation of mental disorders remains relatively unexplored. Our study aimed to examine the influence of polygenic risk scores (PRS) on sub-clinical outcomes over a 2-year period in youth at familial high risk for schizophrenia and bipolar disorder and controls. The sample included 222 children and adolescents, comprising offspring of parents with schizophrenia (n = 38), bipolar disorder (n = 80), and community controls (n = 104). We calculated PRS for psychiatric disorders, neuroticism and cognition using the PRS-CS method. Linear mixed-effects models were employed to investigate the association between PRS and cognition, symptom severity and functioning. Mediation analyses were conducted to explore whether clinical features acted as intermediaries in the impact of PRS on functioning outcomes. SZoff exhibited elevated PRS for schizophrenia. In the entire sample, PRS for depression, neuroticism, and cognitive traits showed associations with sub-clinical features. The effect of PRS for neuroticism and general intelligence on functioning outcomes were mediated by cognition and symptoms severity, respectively. This study delves into the interplay among genetics, the emergence of sub-clinical symptoms and functioning outcomes, providing novel evidence on mechanisms underpinning the continuum from sub-threshold features to the onset of mental disorders. The findings underscore the interplay of genetics, cognition, and clinical features, providing insights for personalized early interventions.

Using brain structural neuroimaging measures to predict psychosis onset for individuals at clinical high-risk.

Machine learning approaches using structural magnetic resonance imaging (sMRI) can be informative for disease classification, although their ability to predict psychosis is largely unknown. We created a model with individuals at CHR who developed psychosis later (CHR-PS+) from healthy controls (HCs) that can differentiate each other. We also evaluated whether we could distinguish CHR-PS+ individuals from those who did not develop psychosis later (CHR-PS-) and those with uncertain follow-up status (CHR-UNK). T1-weighted structural brain MRI scans from 1165 individuals at CHR (CHR-PS+, n = 144; CHR-PS-, n = 793; and CHR-UNK, n = 228), and 1029 HCs, were obtained from 21 sites. We used ComBat to harmonize measures of subcortical volume, cortical thickness and surface area data and corrected for non-linear effects of age and sex using a general additive model. CHR-PS+ (n = 120) and HC (n = 799) data from 20 sites served as a training dataset, which we used to build a classifier. The remaining samples were used external validation datasets to evaluate classifier performance (test, independent confirmatory, and independent group [CHR-PS- and CHR-UNK] datasets). The accuracy of the classifier on the training and independent confirmatory datasets was 85% and 73% respectively. Regional cortical surface area measures-including those from the right superior frontal, right superior temporal, and bilateral insular cortices strongly contributed to classifying CHR-PS+ from HC. CHR-PS- and CHR-UNK individuals were more likely to be classified as HC compared to CHR-PS+ (classification rate to HC: CHR-PS+, 30%; CHR-PS-, 73%; CHR-UNK, 80%). We used multisite sMRI to train a classifier to predict psychosis onset in CHR individuals, and it showed promise predicting CHR-PS+ in an independent sample. The results suggest that when considering adolescent brain development, baseline MRI scans for CHR individuals may be helpful to identify their prognosis. Future prospective studies are required about whether the classifier could be actually helpful in the clinical settings.

Mapping gray and white matter volume abnormalities in early-onset psychosis: an ENIGMA multicenter voxel-based morphometry study.

INTRODUCTION: Regional gray matter (GM) alterations have been reported in early-onset psychosis (EOP, onset before age 18), but previous studies have yielded conflicting results, likely due to small sample sizes and the different brain regions examined. In this study, we conducted a whole brain voxel-based morphometry (VBM) analysis in a large sample of individuals with EOP, using the newly developed ENIGMA-VBM tool. METHODS: 15 independent cohorts from the ENIGMA-EOP working group participated in the study. The overall sample comprised T1-weighted MRI data from 482 individuals with EOP and 469 healthy controls. Each site performed the VBM analysis locally using the standardized ENIGMA-VBM tool. Statistical parametric T-maps were generated from each cohort and meta-analyzed to reveal voxel-wise differences between EOP and healthy controls as well as the individual-based association between GM volume and age of onset, chlorpromazine (CPZ) equivalent dose, and other clinical variables. RESULTS: Compared with healthy controls, individuals with EOP showed widespread lower GM volume encompassing most of the cortex, with the most marked effect in the left median cingulate (Hedges' g = 0.55, p = 0.001 corrected), as well as small clusters of lower white matter (WM), whereas no regional GM or WM volumes were higher in EOP. Lower GM volume in the cerebellum, thalamus and left inferior parietal gyrus was associated with older age of onset. Deficits in GM in the left inferior frontal gyrus, right insula, right precentral gyrus and right superior frontal gyrus were also associated with higher CPZ equivalent doses. CONCLUSION: EOP is associated with widespread reductions in cortical GM volume, while WM is affected to a smaller extent. GM volume alterations are associated with age of onset and CPZ equivalent dose but these effects are small compared to case-control differences. Mapping anatomical abnormalities in EOP may lead to a better understanding of the role of psychosis in brain development during childhood and adolescence.

Cognitive predictors of transition and remission of psychosis risk syndrome in a child and adolescent sample: longitudinal findings from the CAPRIS study.

Cognitive impairments are proposed as predictors in the differentiation between subjects with psychosis risk syndrome (PRS) who will develop a psychotic disorder (PRS-P) and those who will not (PRS-NP). More in-depth study of the PRS-NP group could contribute to defining the role of cognitive alterations in psychosis. This study aims to analyze cognition of children and adolescents with PRS in terms of their clinical outcome at 18-month follow-up (psychosis, remission, and non-remission) and of determinate predictors of transition to psychosis and remission of PRS. The method is two-site, naturalistic, longitudinal study design, with 98 help-seeking adolescents with PRS and 64 healthy controls (HC). PRS-P (n = 24) and PRS-NP (n = 74) participants were clinically and cognitively assessed at baseline, and when full-blown psychotic disorder had developed or at 18-month follow-up. PRS-P subjects showed lower scores at baseline in processing speed, visuospatial memory, attention, and executive function (cognitive flexibility/processing speed) compared to HC. PRS-NP subjects showed lower baseline scores in verbal working memory and verbal fluency compared to HC. This deficit is also observed in the PRS group of participants still presenting attenuated psychotic symptoms at 18-month follow-up, while PRS subjects in remission showed a similar cognitive profile to HC subjects. Baseline score on processing speed, measured with a coding task, appeared to be a predictive variable for the development of a psychotic disorder. Performance in verbal working memory was predictive of remission in the PRS-NP. Post hoc comparisons indicate the need for careful interpretation of cognitive markers as predictors of psychosis. Cognitive impairments are present in both PRS-P and PRS-NP. Those individuals who recover from PRS show baseline cognitive performance comparable to the HC group. Together with sociodemographic variables, this observation could help in the differentiation of a variety of PRS trajectories in children and adolescents.

Altered Temporal Dynamics of Resting-State Functional Magnetic Resonance Imaging in Adolescent-Onset First-Episode Psychosis.

BACKGROUND: Dynamic functional connectivity (dFC) alterations have been reported in patients with adult-onset and chronic psychosis. We sought to examine whether such abnormalities were also observed in patients with first episode, adolescent-onset psychosis (AOP), in order to rule out potential effects of chronicity and protracted antipsychotic treatment exposure. AOP has been suggested to have less diagnostic specificity compared to psychosis with onset in adulthood and occurs during a period of neurodevelopmental changes in brain functional connections. STUDY DESIGN: Seventy-nine patients with first episode, AOP (36 patients with schizophrenia-spectrum disorder, SSD; and 43 with affective psychotic disorder, AF) and 54 healthy controls (HC), aged 10 to 17 years were included. Participants underwent clinical and cognitive assessments and resting-state functional magnetic resonance imaging. Graph-based measures were used to analyze temporal trajectories of dFC, which were compared between patients with SSD, AF, and HC. Within patients, we also tested associations between dFC parameters and clinical variables. STUDY RESULTS: Patients with SSD temporally visited the different connectivity states in a less efficient way (reduced global efficiency), visiting fewer nodes (larger temporal modularity, and increased immobility), with a reduction in the metabolic expenditure (cost and leap size), relative to AF and HC (effect sizes: Cohen's D, ranging 0.54 to.91). In youth with AF, these parameters did not differ compared to HC. Connectivity measures were not associated with clinical severity, intelligence, cannabis use, or dose of antipsychotic medication. CONCLUSIONS: dFC measures hold potential towards the development of brain-based biomarkers characterizing adolescent-onset SSD.

Obsessive-Compulsive Spectrum Symptoms Are Associated With Functional Impairment in Children and Adolescents With Psychosis Risk Syndrome: The CAPRIS Study.

Objective: To compare clinical and functional variables among 3 groups of children and adolescents: subjects at clinical high risk for psychosis (CHR-P) who also have obsessive-compulsive symptoms (OCS), CHR-P patients without OCS, and healthy controls (HC).Methods: A total of 128 CHR-P patients and 98 HC between the ages of 10 and 17 years were recruited as part of a multicenter prospective longitudinal study conducted in Spain between January 1, 2011, and December 31, 2018, with diagnoses made for CHR-P using the Scale of Prodromal Symptoms (SOPS). Two groups were obtained based on Leyton Obsessional Inventory-Child Version (LOI-CV) scores: 64 CHR-P patients with OCS (OCS+) and 64 CHR-P patients without OCS (OCS-). Clinical variables were analyzed with a generalized linear model.Results: Overall, 128 CHR-P patients, 64 (50%) with OCS (mean ± SD age = 15.5 ± 1.4 years, 34.4% male), 64 CHR-P patients without OCS (mean ± SD age = 15.1 ± 1.9 years, 34.4% male), and 98 HC (mean ± SD age = 15.5 ± 1.5 years, 42.9% male), of whom 19 (19.5%) had OCS, were included. Generalized linear model analysis revealed significant differences between the groups. The OCS+ group showed more severe prodromal symptoms (P = .007), worse functioning at baseline (P = .044) and during the previous year (P = .004), and more dysmorphophobic symptoms (P < .001) compared to the OCS- group. OCS+ patients were also more frequently treated with antidepressants (P = .004) than were OCS- patients.Conclusions: In our sample, among children and adolescents with CHR-P, the prevalence of OCS was high (50%). OCS+ subjects had a more severe clinical and functional profile than OCS- subjects. Early detection and treatment of these symptoms can lead to better outcomes for these patients.

Delusional beliefs in adolescents with anorexia nervosa, obsessive-compulsive disorder, or first-episode psychosis: A comparative study.

Delusional thinking is a key symptom of first-episode psychosis (FEP), but it has also been studied in obsessive-compulsive disorder (OCD) and anorexia nervosa (AN). This study aimed to analyze the psychometric properties of the Brown Assessment of Beliefs Scale (BABS) in a sample of adolescents diagnosed with a FEP, AN, or OCD, and to compare delusional thinking among the three samples. The sample comprised 60 patients in three groups of 20 diagnosed with OCD, AN, or FEP. Participants underwent assessment by diagnostic interview, the BABS scale, and a measure of depressive symptomatology. Specific instruments were also used to assess the main symptomatology of each disorder. The BABS had good internal consistency, and high validity and reliability. The OCD group scored significantly lower than the other two groups in all scale items except for items 4 (fixation of ideas), 6 (insight), and 7 (delusions of reference). A significant difference only existed between the AN and FEP groups for item 7 (delusions of reference). The BABS scale is a valid and reliable tool for assessing delusionality in adolescents diagnosed with OCD, AN, or FEP, with evidence of marked differences between the disorders. Assessing these symptoms could influence management, helping to improve treatment adherence and prognosis.

Debate: Child and adolescent mental health services: time to take the lead in prevention of psychosis in youth.

Children and adolescents are at risk of developing mental disorders that have lifelong consequences. This debate piece argues that youth meeting the criteria for clinical high risk for psychosis cannot be assessed and treated with the same tools as adults, given that they often present with different patterns and timecourse of symptoms, age-specific comorbidities and follow different pathways to care. It looks at the key role that Child and Adolescent Mental Health Services and other professionals can play by using an age-specific approach to detecting and preventing psychosis.

Age-related change in cortical thickness in adolescents at clinical high risk for psychosis: a longitudinal study.

Progression to psychosis has been associated with increased cortical thinning in the frontal, temporal and parietal lobes in individuals at clinical high risk for the disorder (CHR-P). The timing and spatial extent of these changes are thought to be influenced by age. However, most evidence so far stems from adult samples. Longitudinal studies are essential to understanding the neuroanatomical changes associated to transition to psychosis during adolescence, and their relationship with age. We conducted a longitudinal, multisite study including adolescents at CHR-P and healthy controls (HC), aged 10-17 years. Structural images were acquired at baseline and at 18-month follow-up. Images were processed with the longitudinal pipeline in FreeSurfer. We used a longitudinal two-stage model to compute the regional cortical thickness (CT) change, and analyze between-group differences controlling for age, sex and scan, and corrected for multiple comparisons. Linear regression was used to study the effect of age at baseline. A total of 103 individuals (49 CHR-P and 54 HC) were included in the analysis. During follow-up, the 13 CHR-P participants who transitioned to psychosis exhibited greater CT decrease over time in the right parietal cortex compared to those who did not transition to psychosis and to HC. Age at baseline correlated with longitudinal changes in CT, with younger individuals showing greater cortical thinning in this region. The emergence of psychosis during early adolescence may have an impact on typical neuromaturational processes. This study provides new insights on the cortical changes taking place prior to illness onset.

Epigenetic age deacceleration in youth at familial risk for schizophrenia and bipolar disorder.

Epigenetic modifications occur sequentially during the lifespan, but their pace can be altered by external stimuli. The onset of schizophrenia and bipolar disorder is critically modulated by stressors that may alter the epigenetic pattern, a putative signature marker of exposure to environmental risk factors. In this study, we estimated the age-related epigenetic modifications to assess the differences between young individuals at familial high risk (FHR) and controls and their association with environmental stressors. The sample included 117 individuals (6-17 years) at FHR (45%) and a control group (55%). Blood and saliva samples were used estimate the epigenetic age with six epigenetic clocks through methylation data. Environmental risk was measured with obstetric complications, socioeconomic statuses and recent stressful life events data. Epigenetic age was correlated with chronological age. FHR individuals showed epigenetic age deacceleration of Horvath and Hannum epigenetic clocks compared to controls. No effect of the environmental risk factors on the epigenetic age acceleration could be detected. Epigenetic age acceleration adjusted by cell counts showed that the FHR group was deaccelerated also with the PedBE epigenetic clock. Epigenetic age asynchronicities were found in the young at high risk, suggesting that offspring of affected parents follow a slower pace of biological aging than the control group. It still remains unclear which environmental stressors orchestrate the changes in the methylation pattern. Further studies are needed to better characterize the molecular impact of environmental stressors before illness onset, which could be critical in the development of tools for personalized psychiatry.

Polygenic Scores and Onset of Major Mood or Psychotic Disorders Among Offspring of Affected Parents.

OBJECTIVE: Family history is an established risk factor for mental illness. The authors sought to investigate whether polygenic scores (PGSs) can complement family history to improve identification of risk for major mood and psychotic disorders. METHODS: Eight cohorts were combined to create a sample of 1,884 participants ages 2-36 years, including 1,339 offspring of parents with mood or psychotic disorders, who were prospectively assessed with diagnostic interviews over an average of 5.1 years. PGSs were constructed for depression, bipolar disorder, anxiety, attention deficit hyperactivity disorder (ADHD), schizophrenia, neuroticism, subjective well-being, p factor, and height (as a negative control). Cox regression was used to test associations between PGSs, family history of major mental illness, and onsets of major mood and psychotic disorders. RESULTS: There were 435 onsets of major mood and psychotic disorders across follow-up. PGSs for neuroticism (hazard ratio=1.23, 95% CI=1.12-1.36), schizophrenia (hazard ratio=1.15, 95% CI=1.04-1.26), depression (hazard ratio=1.11, 95% CI=1.01-1.22), ADHD (hazard ratio=1.10, 95% CI=1.00-1.21), subjective well-being (hazard ratio=0.90, 95% CI=0.82-0.99), and p factor (hazard ratio=1.14, 95% CI=1.04-1.26) were associated with onsets. After controlling for family history, neuroticism PGS remained significantly positively associated (hazard ratio=1.19, 95% CI=1.08-1.31) and subjective well-being PGS remained significantly negatively associated (hazard ratio=0.89, 95% CI=0.81-0.98) with onsets. CONCLUSIONS: Neuroticism and subjective well-being PGSs capture risk of major mood and psychotic disorders that is independent of family history, whereas PGSs for psychiatric illness provide limited predictive power when family history is known. Neuroticism and subjective well-being PGSs may complement family history in the early identification of persons at elevated risk.

What Role for Long-Acting Injectable Antipsychotics in Managing Schizophrenia Spectrum Disorders in Children and Adolescents? A Systematic Review.

BACKGROUND: Long-acting injectable antipsychotics (LAIAs) are an efficacious and well-tolerated treatment in adults with schizophrenia spectrum disorders (SSD). However, there is less evidence for their use in children and adolescents. OBJECTIVES: The aim of this systematic review was to summarize findings regarding the effectiveness and side effects of LAIA in children and adolescents with SSD. METHODS: Four databases (Web of Science, PubMed, MEDES, and Dialnet) were systematically searched for articles published between inception and 12 March, 2022, with the following inclusion criteria: (1) original articles or case reports; (2) providing data on efficacy/effectiveness or safety/tolerability of LAIA treatment in children and adolescents diagnosed with SSD (schizophrenia, schizoaffective disorder, schizophreniform disorder, non-affective psychotic disorder); (3) mean age of samples ≤ 18 years; and (4) written in English or Spanish. Exclusion criteria were review articles, clinical guides, expert consensus as well as posters or oral communication in conferences. The risk of bias was assessed using the ROBIS tool. RESULTS: From 847 articles found, 13 met the inclusion criteria. These included seven single case reports or case series, four retrospective chart reviews, a 24-week open-label trial, and one observational prospective study, covering a total of 119 adolescents (aged 12-17 years) with SSD. Almost all the articles described data on second-generation LAIA (53 patients on risperidone [once every other week], 33 on paliperidone palmitate [once monthly], 10 on aripiprazole [once monthly], and two on olanzapine pamoate [once monthly]). Twenty-one patients were reported to be only on first-generation LAIAs. Non-adherence was the main reason for starting an LAIA. In all of the studies, the use of LAIAs was associated with improvement in the patients' symptoms. CONCLUSIONS: There are few studies assessing the use of LAIAs in adolescents with SSD. Overall, these treatments have suggested good effectiveness and acceptable safety and tolerability. However, we found no studies examining their use in children aged < 12 years. The problems and benefits linked to this type of antipsychotic formulation in the child and adolescent population require further study, ideally with prospective, controlled designs.

Longitudinal Changes in Cortical Surface Area Associated With Transition to Psychosis in Adolescents at Clinical High Risk for the Disease.

OBJECTIVE: Identifying biomarkers of transition to psychosis in individuals at clinical high risk for psychosis (CHR-P) is essential to understanding the mechanisms underlying the disease. Although cross-sectional abnormalities in cortical surface area (CSA) have been demonstrated in individuals at CHR-P who transition to psychosis (CHR-P-T) compared with those who do not (CHR-P-NT), how CSA longitudinally develops remains unclear, especially in younger individuals. We set out to compare CSA in adolescents at CHR-P and healthy controls (HC) over 2 points in time. METHOD: A longitudinal multicenter study was performed in adolescents at CHR-P in comparison to HC and according to transition to psychosis. Magnetic resonance imaging scans were acquired at baseline, at 18-month follow-up, or at the time of transition. Images were pre-processed and hemisphere and regional CSA were computed using FreeSurfer. Between-group analyses were performed with linear mixed-effects models. RESULTS: A total of 313 scans (107 CHR-P and 102 HC) were included in the analysis. At 18 months, the rate of transition to psychosis in CHR-P was 23.4%. Adolescents at CHR-P-T presented greater age-related decrease in CSA in the left parietal and occipital lobes compared with HC, and in the bilateral parietal lobe and right frontal lobe relative to CHR-P-NT. These results were not influenced by antipsychotic treatment, cannabis use, or intelligence quotient (IQ). CONCLUSION: Adolescents at CHR-P that developed a psychotic disorder presented different developmental trajectories of CSA relative to those who did not. A relatively greater decrease in CSA in the parietal and frontal lobes may index clinical transition to psychosis in adolescents at CHR-P.

In vivo white matter microstructure in adolescents with early-onset psychosis: a multi-site mega-analysis.

Emerging evidence suggests brain white matter alterations in adolescents with early-onset psychosis (EOP; age of onset <18 years). However, as neuroimaging methods vary and sample sizes are modest, results remain inconclusive. Using harmonized data processing protocols and a mega-analytic approach, we compared white matter microstructure in EOP and healthy controls using diffusion tensor imaging (DTI). Our sample included 321 adolescents with EOP (median age = 16.6 years, interquartile range (IQR) = 2.14, 46.4% females) and 265 adolescent healthy controls (median age = 16.2 years, IQR = 2.43, 57.7% females) pooled from nine sites. All sites extracted mean fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for 25 white matter regions of interest per participant. ComBat harmonization was performed for all DTI measures to adjust for scanner differences. Multiple linear regression models were fitted to investigate case-control differences and associations with clinical variables in regional DTI measures. We found widespread lower FA in EOP compared to healthy controls, with the largest effect sizes in the superior longitudinal fasciculus (Cohen's d = 0.37), posterior corona radiata (d = 0.32), and superior fronto-occipital fasciculus (d = 0.31). We also found widespread higher RD and more localized higher MD and AD. We detected significant effects of diagnostic subgroup, sex, and duration of illness, but not medication status. Using the largest EOP DTI sample to date, our findings suggest a profile of widespread white matter microstructure alterations in adolescents with EOP, most prominently in male individuals with early-onset schizophrenia and individuals with a shorter duration of illness.