Schizophrenia is a mental disorder which is characterized by abnormalities in the perception of reality. A schizophrenic patient suffers from distortions in perception, which may affect the senses of sight and hearing, especially causing auditory hallucinations, paranoid delusions, or disorganized speech and thinking with significant social or occupational dysfunction. Schizophrenia derives from Greek and means divided or split mind: "Schizo", divided; "Phrenia", mind. This means that someone who suffers from this mental disease lacks integrity; its mental or cerebral functions and areas are not integrated into one coherent, rational whole.
A schizophrenic person may show auditory hallucinations, delusions, and disorganized and unusual thinking and speech, which range from loss of train of thought and subject flow, with sentences only loosely connected in meaning, to incoherence, known as word salad, in severe cases. Social isolation commonly occurs for a variety of reasons. Impairment in social cognition is associated with schizophrenia, as are symptoms of paranoia from delusions and hallucinations, and apathy or lack of motivation. Whether it is genetic, or caused by a negative early environment, it has been shown that a schizophrenic does not have the frontal lobe fully integrated to the rest of his cerebral cortex. This is caused by two reasons: 1) when blood irrigation in this region of the cerebrum is not effective; 2) when the white matter of the frontal lobe is poorly myelinated and thus inefficient connections between neurons.