Schizophrenia comes in two phenomenological forms – Type 1 which is often accompanied by hallucinations, delusions and disorganized thinking and Type 2 which is often accompanied by cognitive deficits and disturbances in social and affective functions 115. The disorder is considered a developmental disorder because several perturbations during pregnancy are known to increase risk, and furthermore schizophrenia-associated gene and epigenetic factors point to early cortical development 116,117. In particular, schizophrenia-associated DNA methylation is closely related to cellular and transcriptome changes occurring during the transition between pre and postnatal life 118. Neuropathological studies of Schizophrenia have revealed reduced brain volume, cell size, and spine density as well as altered neuronal distribution in the prefrontal cortex and hippocampus compared to controls 119–123. Furthermore, pharmacological studies have shown that NMDA receptor antagonists, such as ketamine and phencyclidine (PCP), can cause psychotic and cognitive abnormalities reminiscent of schizophrenia, indicating some detrimental effect caused by reduced glutamate in SCZD 124–126.
