In the study entitled “MRI Anatomy of Schizophrenia,” McCarley et al (1999) examine and analyze the results of 118 peer–reviewed studies with control group from 1987 to May 1998 that used Magnetic Resonance Imaging (MRI) to study the brains of subjects afflicted with schizophrenia. The purpose of the study was to determine what, if any, anomalous brain structures or other abnormalities were present in the brains of each of the study’s participants, with an eye towards assessing if any existing abnormalities presented in discernible patterns or statistically-significant numbers. To qualify for inclusion in this research analysis, each of the peer-reviewed studies had to have included a minimum of ten subjects who had all been diagnosed with schizophrenia and had previously developed observable symptoms.
The participants in each of the peer-reviewed studies were subjected to MRI examinations of the brain with the aim of developing images of the entire structure for examination and comparison with other subjects. The data gathered by McCarley et al turned up a number of statistically-significant findings, as a large percentage of the aggregate population of the earlier studies showed a number of structural anomalies and other abnormalities that were common to the overall group. Lateral ventricle enlargement was seen in 77% of the group and third ventricle enlargement was seen in 67% of the group. Volume decreases in several regions of the brain were also seen in a significant number of participants, as were a number of notable alterations in the temporal lobes of many of the participants.
The researchers began their analysis of these studies based on the hypothesis that schizophrenia is a disorder that is associated with structural defects and abnormalities of the brain, rather than simply a disorder related to neurotransmission. The findings and conclusions reached during this analysis of a large number of studies seems to support the original hypothesis, as a significant number of structural abnormalities were seen in the studies, and virtually every participant in each of the individual studies demonstrated some form of structural abnormality. These findings demonstrate the link between the structure and function of the brain and the behaviors and symptoms associated with schizophrenia.
McCarley, R. W., Wible, C. G., Frumin, M., Hirayasu, Y., Levitt, J. J., Fischer, !. A., & Shention, M. E. (1999). MRI anatomy of schizophrenia. Biological Psychiatry, 45(9), 1099-1119.