Neurobiology of schizophrenia

Schizophrenia clearly involves changes in the structure and functioning of the brain, particularly in the cerebal cortex. This has been established by many computed tomography, magnetic resonance imaging, single photon emission computed tomography and positron emission tomography studies. Earlier studies have typically employed small sample sizes and the selection of controls is important in determining whether significant differences are found. For this reason it remains tantalizingly unclear which parts of the brain are structurally and functionally abnormal. This year's publications are making significant inroads into these issues by employing large sample sizes with careful matching of patients and control individuals, together with increasingly sophisticated methods of image analysis. The evidence looks increasingly strong that schizophrenia involves abnormalities of frontotemporal connections involving amino acid neurotransmitters and that some of these changes may arise from impaired development of normal brain asymmetries.