Environment, Pregnancy, and Fetal Development
The environmental stressors that seem to affect the development of neurodevelopmental disorders tend to revolve around prenatal complications in the early stages of development. Some common complications that can cause the development of neurodevelopmental disorders include maternal illness, poor maternal nutrition, and low birth weight or premature birth (Selemon, 2015). It is believed that the immune response presented by a mother who is sick with either influenza or rubella can change the developmental trajectory of a genetically as risk fetus (Selemon, 2015). It has been theorized that cortical development in the first trimester must be derailed by some environmental factors in early gestation (Selemon, 2015). For example, schizophrenics are known to have decreased neuronal volume, most likely initiated by reducing neuronal proliferation in early gestation (Selemon 2015). An environmental factor that might disrupt the development of the fetus’s cortex is the inflammatory immune response of the mother (Selemon, 2015). The interaction between genes and environment leads to the development of symptoms that usually emerge in late adolescence to early adulthood (Selemon, 2015). These interactions change developmental trajectories, leading to anatomical and functional deficits.
Psychosis – Brain Regions Affected
Numerous regions of the brain are affected by the presence of psychosis. Areas of cortical deficits include, right dorsolateral prefrontal, bilateral medial prefrontal, bilateral ventrolateral prefrontal and insular cortical areas, left medial temporal, as well as thalamus (bilateral), left superior temporal cortex, and minor right cerebellar and right temporal pole areas (Nenadic, 2015). It is understood that individuals suffering from schizophrenia have gross anatomical changes. Particularly in males that display negative symptoms, there are enlarged ventricles (Johnstone, 1976). In fact, there is an overall decrease in brain volume, seen in total brain size (Meyer, 2019). This includes areas like the prefrontal cortex and hippocampus, along with a widening of brain sulci (Meyer, 2019). The brain volume loss in schizophrenics is not a whole scale neurodegeneration like we see in Parkinson’s and Huntington’s disease. Instead, the area of synaptic contacts is largely what is lost (Meyer, 2019). There is no loss of cells bodies, but loss of all the synaptic contacts due to abnormal or excessive pruning of synapses (Meyer, 2019). Additionally, there is disorganized brain anatomy seen in the prefrontal cortex and hippocampus. The disorganized anatomy seen in schizophrenia leads to functional deficits (Meyer, 2019). It is believed that the negative and cognitive symptoms of schizophrenia are the result of inefficient PFC function (Meyer, 2019).
