Understanding deviations from typical brain development is a promising approach to comprehend pathophysiology in childhood and adolescence. We investigated if cerebellar volumes different than expected for age and sex could predict psychopathology, executive functions and academic achievement.

Children and adolescents aged 6–17 years from the Brazilian High-Risk Cohort Study for Mental Conditions had their cerebellar volume estimated using Multiple Automatically Generated Templates from T1-weighted images at baseline (n = 677) and at 3-year follow-up (n = 447). Outcomes were assessed using the Child Behavior Checklist and standardized measures of executive functions and school achievement. Models of typically developing cerebellum were based on a subsample not exposed to risk factors and without mental-health conditions (n = 216). Deviations from this model were constructed for the remaining individuals (n = 461) and standardized variation from age and sex trajectory model was used to predict outcomes in cross-sectional, longitudinal and mediation analyses.

Cerebellar volumes higher than expected for age and sex were associated with lower externalizing specific factor and higher executive functions. In a longitudinal analysis, deviations from typical development at baseline predicted inhibitory control at follow-up, and cerebellar deviation changes from baseline to follow-up predicted changes in reading and writing abilities. The association between deviations in cerebellar volume and academic achievement was mediated by inhibitory control.

Deviations in the cerebellar typical development are associated with outcomes in youth that have long-lasting consequences. This study highlights both the potential of typical developing models and the important role of the cerebellum in mental health, cognition and education.

Mental disorders can have a major impact on brain development. Peripheral blood concentrations of brain-derived neurotrophic factor (BDNF) are lower in adult psychiatric disorders. Serum BDNF concentrations and BDNF genotype have been associated with cortical maturation in children and adolescents. In 2 large independent samples, this study tests associations between serum BDNF concentrations, brain structure, and psychopathology, and the effects of BDNF genotype on BDNF serum concentrations in late childhood and early adolescence.

Children and adolescents (7-14 years old) from 2 cities (n = 267 in Porto Alegre; n = 273 in São Paulo) were evaluated as part of the Brazilian high-risk cohort (HRC) study. Serum BDNF concentrations were quantified by sandwich ELISA. Genotyping was conducted from blood or saliva samples using the SNParray Infinium HumanCore Array BeadChip. Subcortical volumes and cortical thickness were quantified using FreeSurfer. The Development and Well-Being Behavior Assessment was used to identify the presence of a psychiatric disorder.

Serum BDNF concentrations were not associated with subcortical volumes or with cortical thickness. Serum BDNF concentration did not differ between participants with and without mental disorders, or between Val homozygotes and Met carriers.

No evidence was found to support serum BDNF concentrations as a useful marker of developmental differences in brain and behavior in early life. Negative findings were replicated in 2 of the largest independent samples investigated to date.

Oxidative stress has been documented in chronic schizophrenia and in the first episode of psychosis, but there are very little data on oxidative stress prior to the disease onset.

This work aimed to compare serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in young individuals at ultra-high risk (UHR) of developing psychosis with a comparison healthy control group (HC).

Thirteen UHR subjects and 29 age- and sex-matched healthy controls (HC) were enrolled in this study. Clinical assessment included the Comprehensive Assessment of At-Risk Mental States (CAARMS), the Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I) or the Kiddie-SADS-Present and Lifetime Version (K-SADS-PL), and the Global Assessment of Functioning (GAF) scale. Activities of SOD and GPx were measured in serum by the spectrophotometric method using enzyme-linked immunosorbent assay kits.

After adjusting for age and years of education, there was a significant lower activity of SOD and lower GPX activity in the UHR group compared to the healthy control group (rate ratio [RR]=0.330, 95% CI 0.187; 0.584, p<0.001 and RR=0.509, 95% CI 0.323; 0.803, p=0.004, respectively). There were also positive correlations between GAF functioning scores and GPx and SOD activities.

Our results suggest that oxidative imbalances could be present prior to the onset of full-blown psychosis, including in at-risk stages. Future studies should replicate and expand these results.