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Cognition in high-risk groups

Who are people at high-risk of psychosis?

There are two key approaches for identifying people with early signs that may suggest a high risk of developing psychosis or schizophrenia. The first approach is based on Huber’s Basic Symptoms, which focuses on a detailed way of describing phenomenological (subjective) disturbances. Because the basic symptoms refer only to subtle subjectively experienced abnormalities, they may reflect an earlier phase in the disease process than the second approach, which identifies at-risk mental states as a combination of; a family history of psychosis (familial risk) plus non-specific symptoms and recent decline in functioning; recent onset Attenuated Psychotic Symptoms with decline in functioning; and Brief Limited Intermittent Psychotic Symptoms.

What is the evidence for cognitive functioning in high-risk groups?

High quality evidence shows a small to medium-sized effect of lower general intelligence, poor executive functioning, attention, visual memory, and social cognition in people at high risk of psychosis compared to people who are not at high risk of psychosis. Moderate to high quality evidence also suggests lower visual-spatial ability, olfactory functioning, verbal fluency, verbal memory, working memory, and learning. High quality evidence suggests people at clinical high risk of psychosis and familial high risk of psychosis are similarly impaired on processing speed, verbal and visual memory, attention and language fluency when compared with controls. People at familial high risk were more impaired on premorbid and current IQ than people at clinical high risk, and people at clinical high risk were more impaired on visuospatial working memory than people at familial high risk. Moderate quality evidence showed that people at high risk who converted to psychosis showed a medium-sized effect of lower olfactory functioning, general cognitive ability, language functioning, visual-spatial ability, memory, attention and executive functioning prior to conversion than people not at high risk of psychosis. Compared to people at high risk who did not convert to psychosis, moderate quality evidence showed that people at high risk who did converted to psychosis showed small to medium-sized effects of poor visual learning and working memory. Moderate to low quality evidence also suggests a medium-sized effect of lower general intelligence, verbal fluency, verbal memory, and visual memory.

 

April 2016

Page last updated: 3:48  6 September 2017

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