Schizophrenia is a heterogeneous psychiatric disorder broadly accepted being caused by genetic and environmental factors. Although conventional genetic studies have identified some candidate genes for schizophrenia, low odds ratios and penetrance, and a lack of reproducibility have limited their explanatory power. Despite the major efforts made toward identifying environmental factors in schizophrenia, methodological limitations and inconsistent findings of epidemiological reports have obstructed attempts to identify exogenous causal factors. Epigenetic mechanisms, mediating between environment and genes, have recently been proposed to play an important role in the pathogenesis of schizophrenia. DNA methylation is the most stable and well-characterized epigenetic modification. In this paper, we briefly introduce DNA methylation mechanisms, genome-wide DNA methylation studies, and identify specific genomic methylation sites in individuals diagnosed with schizophrenia. The outline candidate genes such as Reelin and COMT, are also outlined before paying attention to the conundrum of recent researches.
Schizophrenia is a severe mental disorder characterized by impaired perception, delusions, thought disorder, abnormal emotion regulation, altered motor function, and impaired drive. The default mode network （DMN）, since it was first proposed in 2001, has become a central research theme in neuropsychiatric disorders, including schizophrenia. In this review, first we define the DMN and describe its functional activity, functional and anatomical connectivity, heritability, and inverse correlation with the task positive network. Second, we review empirical studies of the anatomical and functional DMN, and anti-correlation between DMN and the task positive network in schizophrenia. Finally, we review preliminary evidence about the relationship between antipsychotic medications and regulation of the DMN, review the role of DMN as a treatment biomarker for this disease, and consider the DMN effects of individualized therapies for schizophrenia.
Dear Editor：Numerous magnetic resonance imaging（MRI）studies have demonstrated that patients with early-onset schizophrenia（EOS）have widespread structural abnormalities in the cortical gray matter[1],suggesting that neurobiological processes play a central role in the structural abnormalities underlying the pathophysiology of schizophrenia[2].In addition,volumetric abnormalities have been used to identify individuals at risk of mental states of
