Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh High Risk Study

Background. Studies of groups of individuals who have a genetically high ri sk of developing schizophrenia, have found neuropsychological impairments t hat highlight likely trait markers of the schizophrenic genotype. This pape r describes the change in neuropsychological function and associations with psychiatric state of high risk participants during the first two assessmen ts of the Edinburgh High Risk Study. Methods. Seventy-eight high risk participants and 22 normal controls, age a nd sex matched completed two neuropsychological assessments 18 months to 2 years apart. The areas of function assessed include intellectual function, executive function, learning and memory, and verbal ability and language. Results. The high risk participants performed significantly worse on partic ular tests of verbal memory and executive function over the two assessments than matched controls. Those high risk participants who experienced psycho tic symptoms were found to exhibit a decline in IQ and perform worse on tes ts of verbal memory and executive function than those without symptoms. An increase in psychotic symptoms between the two assessments in the high risk group was found to be associated with an apparent decline in IQ and memory . Conclusions. The results suggest that the development of psychotic symptoms is preceded by a decline in IQ and memory. This may reflect a general and a more specific disease process respectively.