Prior studies suggest that childhood maltreatment is associated with altered hippocampal volume. However, longitudinal studies are currently scarce, making it difficult to determine how alterations in hippocampal volume evolve over time. The current study examined the relationship between childhood maltreatment and hippocampal volumetric development across childhood and adolescence in a community sample.

In this longitudinal study, a community sample of 795 participants underwent brain magnetic resonance imaging (MRI) in three waves spanning ages 6–21 years. Childhood maltreatment was assessed using parent-report and children´s self-report at baseline (6–12 years old). Mixed models were used to examine the relationship between childhood maltreatment and hippocampal volume across time.

The quadratic term of age was significantly associated with both right and left hippocampal volume development. High exposure to childhood maltreatment was associated with reduced offset of right hippocampal volume and persistent reduced volume throughout adolescence.

Critically, the relationship between childhood maltreatment and reduced right hippocampal volume remained significant after adjusting for the presence of any depressive disorder during late childhood and adolescence and hippocampal volume polygenic risk scores. Time-by-CM and Sex-by-CM interactions were not statistically significant.

The present study showed that childhood maltreatment is associated with persistent reduction of hippocampal volume in children and adolescents, even after adjusting for the presence of major depressive disorder and genetic determinants of hippocampal structure.

The current investigation assessed a) the performance of the FOCUS ADHD mobile health application (App) in increasing pharmacological treatment adherence and improving patients’ knowledge of attention-deficit/hyperactivity disorder (ADHD) and b) the impact of implementing a financial incentive for using the App (i.e., a discount on medication).

In a randomized, blind, parallel-group clinical trial, 73 adults diagnosed with ADHD were allocated into three groups for 3 months: a) Pharmacological treatment as usual (TAU); b) TAU and the App (App Group); and c) TAU and the App + a commercial discount on the purchase of medication prescribed for ADHD treatment (App + Discount Group).

There was no significant difference in mean treatment adherence between groups, assessed as a medication possession ratio (MPR). However, the App + Discount Group exhibited greater medication intake registrations compared with the App Group during the initial phase of the trial. The financial discount also produced a 100% App adoption rate. App use did not increase ADHD knowledge, though knowledge scores were high at baseline. The usability and quality of the App were rated favorably.

The FOCUS ADHD App achieved a high adoption rate and positive evaluations by users. Use of the App did not increase adherence to treatment as measured by MPR, but, for App users, the addition of a financial incentive to use the App produced an increase in treatment adherence in terms of medication intake registrations. The present results offer encouraging data for combining incentives with mobile digital health solutions to positively impact treatment adherence in ADHD.

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.