Developmental Dyslexia: Insights from EEG-Based Findings and Molecular Signatures-A Pilot Study.

Developmental dyslexia (DD) is a learning disorder. Although risk genes have been identified, environmental factors, and particularly stress arising from constant difficulties, have been associated with the occurrence of DD by affecting brain plasticity and function, especially during critical neurodevelopmental stages. In this work, electroencephalogram (EEG) findings were coupled with the genetic and epigenetic molecular signatures of individuals with DD and matched controls. Specifically, we investigated the genetic and epigenetic correlates of key stress-associated genes (NR3C1, NR3C2, FKBP5, GILZ, SLC6A4) with psychological characteristics (depression, anxiety, and stress) often included in DD diagnostic criteria, as well as with brain EEG findings. We paired the observed brain rhythms with the expression levels of stress-related genes, investigated the epigenetic profile of the stress regulator glucocorticoid receptor (GR) and correlated such indices with demographic findings. This study presents a new interdisciplinary approach and findings that support the idea that stress, attributed to the demands of the school environment, may act as a contributing factor in the occurrence of the DD phenotype.

Developmental Dyslexia: Environment Matters.

Developmental dyslexia (DD) is a multifactorial, specific learning disorder. Susceptibility genes have been identified, but there is growing evidence that environmental factors, and especially stress, may act as triggering factors that determine an individual's risk of developing DD. In DD, as in most complex phenotypes, the presence of a genetic mutation fails to explain the broad phenotypic spectrum observed. Early life stress has been repeatedly associated with the risk of multifactorial disorders, due to its effects on chromatin regulation, gene expression, HPA axis function and its long-term effects on the systemic stress response. Based on recent evidence, we discuss the potential role of stress on DD occurrence, its putative epigenetic effects on the HPA axis of affected individuals, as well as the necessity of early and appropriate intervention, based on the individual stress-associated (endo)phenotype.

Specific learning difficulties: a retrospective study of their co morbidity and continuity as early indicators of mental disorders.

BACKGROUND: Specific Learning difficulties constitute a continuity of complex disorders, which unfold across the lifespan and are associated with a wide range of mental disorders. In order to determine the importance of specific learning difficulties as an underlying factor in various mental disorders, we investigated associations between mental disorders and factors related to learning difficulties, poor family and school environment, and social and psycho-emotional disorders. METHODS: This retrospective study is based on data from 835 case histories of adults who were treated at the Psychiatric Clinic of the University Hospital in Ioannina, Greece, between 1992 and 2008. The examination of the early (co-)occurrence of specific disorders was based on the ICD-10 classification of mental disorders. LogLinear analysis showed that all models retained 2nd or 3rd order effects with p-values >0.8 for all estimated likelihood ratios. RESULTS: Patients with specific learning difficulties, who grew up in a socially disturbed environment, and manifested behavioral problems (aggression, alcoholism, and isolation or running away from home) were found to be more frequently diagnosed with schizophrenia than with any other mental disorder. In some cases, the profiles of these patients also included family problems such as parental loss or alcoholism. CONCLUSIONS: Significant association between learning and other disorders in adult psychiatric patients' developmental profile has been indicated. Furthermore, a specific association between specific learning difficulties, environmental problems, and schizophrenia corroborates the continuity and complexity of these disorders at higher developmental stages. The results from this study can be utilized in the study of mental disorder etiology, raising the possibility that the early treatment of the learning or other disorders could reduce children's likelihood of developing mental disorders in adulthood.

Learning difficulties: a retrospective study of their co morbidity and continuity as indicators of adult criminal behaviour in 18-70-year-old prisoners.

The development of learning difficulties is associated with problems in external (executive) and extensive behaviour in a co-occurrence with psycho-emotional problems beginning from pre-school, school age, and adolescence up to adulthood. Through the current survey, we aim to emphasise the early role of learning difficulties during the school age and adolescence of prisoners and their effects on the onset of offending behaviours in adulthood, such as criminal behaviour. Altogether, we studied 117 Greek adult prisoners from 18 to 70 years old who were accused of different types or degrees of offences. Through statistical analyses, the following factors were observed with high statistical significance as early indicators of criminal behaviour in the adult lives of the prisoners: (i) learning difficulties, (ii) family problems, (iii) behaviour disorders, (iv) developmental disorders, and (v) psycho-emotional disorders. As a result, the learning difficulties were assumed to be the most decisive factor in the developmental progression of prisoners because they manifested early in the prisoners' lives, weakened the prisoners to be competitive and robust, provoked a bad self-image and low self-esteem, and, in the frame of a weak or negative family and educational environment, they accompanied antisocial behaviour and psycho-emotional disorders even from adolescence, which continued into adulthood.

An interpretative model of early indicators of specific developmental dyslexia in preschool age: a comparative presentation of three studies in Greece.

The detection of specific factors of the developmental dyslexia at an early stage, and the identification of the role of those factors responsible for its manifestation, is a fundamental area of study on dyslexia in the recent literature. The objective of the present study is to clarify that dysfunctions in the following specific domains contribute in a causal model to the occurrence of dyslexia at an early stage: phonological awareness, psychomotor ability (body shape, spatio-temporal orientation, grapho-motor ability and laterality), perception, memory, attention, prereading and prewriting skills. The results of three studies, --carried out in Greece--which revealed the above factors as main predictors of the early onset of Specific Developmental Dyslexia (SDD) and confirmed the importance of intervention methods to it, led us to the construction of the proposed, causal model. The findings of these three studies converge on the perspective that the understanding, diagnosis and treatment of dysfunctions in the above domains, from preschool age, enable the early and reliable prevention of future difficulties in the learning process of children.