Perhaps the most well-known aspect of schizophrenia is the distressing hallucinations and delusions it can cause. However, it can also cause terrible problems with cognition which can be just as damaging. Researchers from Harvard University Medical School and SUNY Upstate Medical University in the U.S. reviewed 47 studies into the effects of first-episode schizophrenia on people's cognition which, between them, covered 4,979 people. They found that even after the first episode of schizophrenia cognitive problems were already broad and serious often being just as bad as the problems of people who had been ill much longer. People experiencing their first episode of schizophrenia performed much worse on tests than healthy control groups and had particular problems with processing speed, verbal learning and memory. Cognitive abilities declined the most between the high-risk period just before symptoms appear and the first acute phases.
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