The dopamine hypothesis has earlier dominated the theories for the
development of schizophrenia based on the early pharmacologic evidence. The
antipsychotic drugs, among others, is thought to interfere with the function of the
dopamine D2 receptor (DRD2) resulting in clinical improvement. Accumulating evidence
suggest the role of epigenetic mechanisms in the pathophysiology of schizophrenia.
Despite this, specific evidence linking the DRD2 DNA methylation with schizophrenia is
insufficient mainly due to the poor accessibility and limited brain samples. Of late, new
data has suggested the global impact of DNA methylation in the development of
schizophrenia, thus methylation in the peripheral blood could infer changes in the brain.
The aim of this study was to assess the DRD2 DNA methylation in the peripheral blood of
schizophrenia.
The dopamine hypothesis of schizophrenia is based on the fact that hyperdopaminergic
state is involved in causing psychosis and antipsychotic drugs block the
dopamine receptor. COMT regulates the homeostatic levels of neurotransmitter
dopamine in the synapses and plays a role in the neurocognitive function. The
dysregulation of dopamine in the prefrontal cortex influences the cognitive function and
the severity of the psychotic symptoms in schizophrenia. During epigenetic event,
methylated COMT gene may cause reduction in its expression and contribute to the
clinical presentation of schizophrenia. Therefore, the aim of this study was to assess the
feasibility of using COMT DNA methylation for the prediction of specific psychotic
presentation of schizophrenia. (Copied from article).