Schizophrenia arises through multiple processes including early/late neurodevelopmental changes occurring at least from initial stage of psychosis, and neurodegenerative change after onset of psychosis. Hence, the prodromal phase of schizophrenia has drawn great attention since 1990s, and many neuroimaging researches have been applied to subjects at high-risk for psychosis, which represent putatively the prodromal phase. The neuroimaging studies of high-risk subjects present clues to further understanding of psychopathology and pathophysiology of psychosis.
We established the Seoul Youth Clinic and provided multidimensional evaluation and intervention for young people at high-risk for psychosis. We have studied on two groups of people at high-risk; the clinical high-risk group is subjects who have psychopathologies related to schizophrenia (such as attenuated or brief intermittent psychotic symptoms), while the genetic high-risk group is nonpsychotic relatives of schizophrenia with high genetic loading which affords the opportunity to realize the influence of genetic loading before the onset of psychosis. Our studies supported that structural and functional brain abnormalities mostly in prefrontal and temporal areas are already present before the onset of psychosis. Recently our neuroimaging studies have shown the relationship between those abnormalities and positive symptoms and between changes of functional connectivity and general psychopathology, which disclosed neural correlates of clinical symptomatology.
Our findings illustrate that structural and functional brain abnormalities precede the psychosis onset. Further longitudinal follow-ups are vital to validate the interpretation of our findings, and to reveal differences in these abnormalities between those who will convert to psychosis later and those who will not.