As noted above, from this sample of UHR individuals, 35% went on to develop schizophrenia within 1 year. Those UHR individuals who go on to develop schizophrenia show medial temporal and prefrontal (particularly orbitofrontal) brain abnormalities, compared with UHR subjects who do not develop schizophrenia. These investigators, also as noted previously, suggest that the brain abnormalities observed in those Inhibitors,research,lifescience,medical who transition to schizophrenia reflect abnormal brain maturation, which occurs with other events such as substance abuse, stress, etc, and likely involves
early neurodevelopmental insults to the brain. This abnormal maturation might then render the brain vulnerable to later abnormal processes, including accelerated gray matter loss in frontotemporal regions, and abnormal connectivity in prefrontal brain regions. A focus on genetics in high-risk studies is also important. For example, the effects of the catechol-Omethyltransferase (COMT) gene Inhibitors,research,lifescience,medical on brain structure and function in high-risk individuals, reported by the Edinburgh group,48 suggests that the risk of developing schizophrenia in the high-risk group is increased in individuals with the COMT Val158Met polymorphism. Thus subtyping of high-risk individuals based on putative brain markers, genes, and outcome, Inhibitors,research,lifescience,medical while just
beginning, will be an Selleckchem COX inhibitor important direction for future studies. Family studies: genetic high risk studies An area of further inquiry is whether or not there are some brain abnormalities that are present in schizophrenia which are also present in nonaffected family members. Such findings would point to potential markers of genetic vulnerability to schizophrenia.
In addition, studying nonaffected family Inhibitors,research,lifescience,medical members avoids the confounds of chronicity and medication, which characterize studies of chronic patients. Further, studying this population is independent of psychosis, thus avoiding the possible neurotoxic effects of psychosis, which may Inhibitors,research,lifescience,medical be brewing even in high-risk populations. Finally, a focus on nonaffected family members makes it possible to study genetic factors as well as environmental factors with respect to their roles in the etiology of schizophrenia. Most of the MRI studies that have investigated nonaffected family members report the severity of brain abnormalities to be midway between healthy controls and patients with these schizophrenia, and similar to what is observed in high-risk individuals.23-26 The brain region most commonly reported as abnormal is the hippocampus, although it should noted that the hippocampus is also one of the most commonly investigated brain region in the relatives of schizophrenic patients. In a recent meta-analysis study by Boos and colleagues,49 25 MRI studies of nonaffected first-degree relatives of patients with schizophrenia were reviewed. The main finding was reduced left hippocampal volume, and increased third ventricle volume.