Is there evidence for neuronal loss in schizophrenia?

Almost all cell counting studies of schizophrenia published between 1972 and 1991 have reported a reduction in the density of neurons in several different corticolimbic regions. More recently, however, several groups have failed to detect a change of this type in the cortex of schizophrenic patients. These discrepant findings are discussed in relation to a variety of factors, including the heterogeneity of patient samples, various ways that tissues have been processed, the use of two-dimensional versus three-dimensional cell counting techniques and differences in the brain regions that were examined tit various studies. Although no single factor can explain the discrepancies, it has become clear that neuronal lass in schizophrenia, where present, is quite subtle and is probably neither necessary nor sufficient to explain the occurrence of this disorder.