Neurological disorders are an enigmatic bunch. There are various ongoing researches to identify the exact cause and how to treat them. While some argue that schizophrenia is a chronic brain disorder, others do not agree with it and debate that the origin is yet to be identified and the factors which produce it are yet to be identified.
Factors supporting it to be a brain disease are listed below.
Scan images (MRI and PET scans) of people who have had schizophrenia are different and have a reduced volume of grey matter, especially in the frontal and temporal lobes. In some people, this loss could be as high as 25%. Serial images have shown that the loss begins in the outer (parietal) region and gradually spreads to the rest of the brain. There is a strong correlation between the extent of this grey matter loss and the severity of the symptoms more the loss, worse the symptoms. Severe symptoms include hearing voices, psychotic thoughts, delusions, hallucinations and severe depression. This grey matter reduction does not depend on whether the person has undergone treatment or not for the condition.
The counter argument is that grey matter loss is not seen in patients with schizophrenia alone. A number of neurological disorders, including normal ageing, manifest as grey matter loss on the scan images. Also, another consoling news is that this grey matter loss is completely reversible.
The way neurotransmitters respond to stimuli in people with schizophrenia is also slightly different. There are two variations to this debate: that schizophrenia is caused by excessive amounts of dopamine or increased sensitivity to dopamine. There are two proofs for this hypothesis first, dopamine suppressants are useful as antipsychotic drugs and secondly drugs which produce the same effect as dopamine can cause hallucinations similar to those seen in schizophrenics. There could be other neurotransmitters involved too, but the dopamine connection is more strongly established.
The electrical activity of the brain as seen in EEG is very different and abnormal in schizophrenic people. This reduced brain activity is another indication of the fact that schizophrenia is another brain disorder. There is also a strong genetic component to schizophrenia. Family history correlation is also very strong. The correlation extends to the point that where there is a neurologic disorder in the first-degree relatives, the chances of developing schizophrenia is increased.
There are specific genes, mutations of which are also attributed to schizophrenia. While the risk factors are in place (as mentioned above), the environmental conditions (brain infections, head trauma, family/social stressors and toxins can all lead to the manifestation of the symptoms. With medications and support therapy, both prevention and symptom management are possible. If you wish to discuss about any specific problem, you can consult a Neurologist.