Schizophrenia: a review, with emphasis on the neurodevelopmental hypothesis

The neurodevelopmental hypothesis of schizophrenia has gained increasing acceptance. This hypothesis assumes a disruption in the normal development of the brain, secondary to genetic factors, environmental factors, or, most likely, a combination of both. After a brief review of the various aetiologic models since the first description of the disease, we review relevant aspects of normal brain development and then focus on the pathologic findings supporting the neurodevelopmental hypothesis. Although this hypothesis of schizophrenia appears to be valid in some cases, it is important to keep in mind that there are many cases of schizophrenia in which one finds no documented brain abnormality. It therefore seems wrong to speak of schizophrenia in general as a neurodevelopmental disorder. It appears that there is a group of patients with schizophrenia who fit into a neurodevelopmental model. There is a need to further investigate whether these patients can be identified clinically and what this may imply with regard to treatment and prognosis.